{"id":"CVE-2026-71886","aliases":["DEBIAN-CVE-2026-71886","EUVD-2026-92002","GHSA-7hrr-mw36-px4x","SUSE-SU-2026:24461-1","SUSE-SU-2026:4797-1","UBUNTU-CVE-2026-71886","openSUSE-SU-2026:12090-1","openSUSE-SU-2026:22169-1"],"status":"published","title":"OpenPGP certification accepted from a subkey without certification authority","description":"In Bouncy Castle for Java before 1.86, the high-level OpenPGP certificate API accepted a third-party certification or trust delegation from any component key of the issuing certificate, without requiring that component to have been granted the authority to certify. OpenPGPCertificate.getCertificationBy() and getDelegationBy() resolve a third-party signature by matching its issuer key identifier against every key of the third-party certificate, then verify the issuing component's binding chain and the signature itself; nothing checked that the issuing component carried the RFC 9580 sec. 5.2.3.29 certification key flag (CERTIFY_OTHER) when the signature was created. A subkey bound only with SIGN_DATA - the online signing subkey of exactly the offline-primary arrangement those key flags exist to express - could therefore issue a positive User ID certification over an attacker-controlled identity, or a full-trust depth-one direct-key delegation of introducer trust, and the API returned it as a valid signature chain attributed to the third-party certificate. An application treating getCertificationBy(...).isValid() or getDelegationBy(...) as an identity or trusted-introducer decision would attribute the attacker's assertion to the offline primary key. The same held for a legacy RSA subkey bound only for encryption, whose algorithm is nonetheless able to sign. This does not forge the primary key's signature or recover any private key; it promotes an already-compromised restricted subkey to the primary key's identity-issuing authority, defeating the containment the key-flag separation provides. A third-party certification or delegation is now attributed to the issuing certificate only when the component key that made it is the primary key, or is a subkey holding CERTIFY_OTHER when the signature was created, so certification-capable subkeys continue to be accepted; primary keys are accepted whatever their key flags say, since a primary key is certification-capable by construction and certificates carrying no key flags subpacket at all are common. Third-party revocations are deliberately outside the rule, since declining to honour one would keep trust alive rather than withdraw it.","severity":{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/U:Amber","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00167,"percentile":0.05961,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-285","CWE-863"],"published":"2026-10-03T08:46:33Z","modified":"2026-11-04T17:27:21Z","fixes":[{"ecosystem":"Debian:14","package":"bouncycastle","fixed_in":["1.86-1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.72-2","1.77-1","1.80-1","1.80-2","1.80-3","1.86-1"]},{"source":"osv","ecosystem":"Debian:13","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.80-3","1.86-1"]},{"source":"osv","ecosystem":"Debian:14","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.86-1"}]}],"versions":["1.80-3"]},{"source":"osv","ecosystem":"SUSE:Linux Enterprise Server 16.0","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.86-160000.1.1"}]}],"bundled":14},{"source":"osv","ecosystem":"SUSE:Linux Enterprise Server for SAP applications 16.0","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.86-160000.1.1"}]}],"bundled":14},{"source":"osv","ecosystem":"SUSE:Linux Enterprise Module for Development Tools 15 SP7","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.86-150200.3.41.1"}]}],"bundled":14},{"source":"osv","ecosystem":"SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.86-150200.3.41.1"}]}],"bundled":14},{"source":"osv","ecosystem":"SUSE:Linux Enterprise High Performance Computing 15 SP4-LTSS","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.86-150200.3.41.1"}]}],"bundled":14},{"source":"osv","ecosystem":"SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.86-150200.3.41.1"}]}],"bundled":14},{"source":"osv","ecosystem":"SUSE:Linux Enterprise High Performance Computing 15 SP5-LTSS","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.86-150200.3.41.1"}]}],"bundled":14},{"source":"osv","ecosystem":"SUSE:Linux Enterprise Server 15 SP4-LTSS","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.86-150200.3.41.1"}]}],"bundled":14},{"source":"osv","ecosystem":"SUSE:Linux Enterprise Server 15 SP5-LTSS","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.86-150200.3.41.1"}]}],"bundled":14},{"source":"osv","ecosystem":"SUSE:Linux Enterprise Server 15 SP6-LTSS","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.86-150200.3.41.1"}]}],"bundled":14},{"source":"osv","ecosystem":"SUSE:Linux Enterprise Server for SAP Applications 15 SP4","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.86-150200.3.41.1"}]}],"bundled":14},{"source":"osv","ecosystem":"SUSE:Linux Enterprise Server for SAP Applications 15 SP5","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.86-150200.3.41.1"}]}],"bundled":14},{"source":"osv","ecosystem":"SUSE:Linux Enterprise Server for SAP Applications 15 SP6","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.86-150200.3.41.1"}]}],"bundled":14},{"source":"osv","ecosystem":"Ubuntu:Pro:16.04:LTS","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.49+dfsg-3ubuntu1","1.51-4ubuntu1","1.51-4ubuntu1+esm1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:18.04:LTS","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.57-1","1.58-1","1.59-1","1.59-1ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.61-1","1.61-1ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:22.04:LTS","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.68-2","1.68-4","1.68-5","1.68-5ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:24.04:LTS","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.72-2","1.77-1","1.77-1ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.80-3"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.80-3"]},{"source":"osv","ecosystem":"openSUSE:Tumbleweed","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.86-1.1"}]}],"bundled":14},{"source":"osv","ecosystem":"openSUSE:Leap 16.0","package":"bouncycastle","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.86-160000.1.1"}]}],"bundled":14}],"products":[{"vendor":"legion of the bouncy castle inc.","product":"bc-java"}],"references":[{"url":"https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%9071886","tags":["vendor-advisory","advisory","report"]},{"url":"https://github.com/bcgit/bc-java/commit/f0d5c8535aeff3f34b7b6b6289ee78c2ea36a3fb","tags":["patch","fix","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-71886","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-7hrr-mw36-px4x"},{"url":"https://www.bouncycastle.org/download/bouncy-castle-java/","tags":["web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/71xxx/CVE-2026-71886.json","tags":["advisory"]},{"url":"https://github.com/bcgit/bc-java","tags":["package"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-71886","tags":["advisory"]},{"url":"https://www.suse.com/support/update/announcement/2026/suse-su-202624461-1/","tags":["advisory"]},{"url":"https://bugzilla.suse.com/1284065","tags":["report"]},{"url":"https://bugzilla.suse.com/1284073","tags":["report"]},{"url":"https://bugzilla.suse.com/1284075","tags":["report"]},{"url":"https://bugzilla.suse.com/1284165","tags":["report"]},{"url":"https://bugzilla.suse.com/1284205","tags":["report"]},{"url":"https://bugzilla.suse.com/1284212","tags":["report"]},{"url":"https://bugzilla.suse.com/1284213","tags":["report"]},{"url":"https://bugzilla.suse.com/1284215","tags":["report"]},{"url":"https://bugzilla.suse.com/1284218","tags":["report"]},{"url":"https://bugzilla.suse.com/1284219","tags":["report"]},{"url":"https://bugzilla.suse.com/1284220","tags":["report"]},{"url":"https://bugzilla.suse.com/1284221","tags":["report"]},{"url":"https://bugzilla.suse.com/1284222","tags":["report"]},{"url":"https://bugzilla.suse.com/1284224","tags":["report"]},{"url":"https://www.suse.com/security/cve/CVE-2026-17507","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-17508","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-18036","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-18040","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-71885","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-71886","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-71887","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-71888","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-71889","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-71890","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-71891","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-71892","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-85515","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-97873","tags":["web"]},{"url":"https://www.suse.com/support/update/announcement/2026/suse-su-20264797-1/","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-71886","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-71886","tags":["report"]},{"url":"","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-71886","title":"OpenPGP certification accepted from a subkey without certification authority","description":"In Bouncy Castle for Java before 1.86, the high-level OpenPGP certificate API accepted a third-party certification or trust delegation from any component key of the issuing certificate, without requiring that component to have been granted the authority to certify. OpenPGPCertificate.getCertificationBy() and getDelegationBy() resolve a third-party signature by matching its issuer key identifier against every key of the third-party certificate, then verify the issuing component's binding chain and the signature itself; nothing checked that the issuing component carried the RFC 9580 sec. 5.2.3.29 certification key flag (CERTIFY_OTHER) when the signature was created. A subkey bound only with SIGN_DATA - the online signing subkey of exactly the offline-primary arrangement those key flags exist to express - could therefore issue a positive User ID certification over an attacker-controlled identity, or a full-trust depth-one direct-key delegation of introducer trust, and the API returned it as a valid signature chain attributed to the third-party certificate. An application treating getCertificationBy(...).isValid() or getDelegationBy(...) as an identity or trusted-introducer decision would attribute the attacker's assertion to the offline primary key. The same held for a legacy RSA subkey bound only for encryption, whose algorithm is nonetheless able to sign. This does not forge the primary key's signature or recover any private key; it promotes an already-compromised restricted subkey to the primary key's identity-issuing authority, defeating the containment the key-flag separation provides. A third-party certification or delegation is now attributed to the issuing certificate only when the component key that made it is the primary key, or is a subkey holding CERTIFY_OTHER when the signature was created, so certification-capable subkeys continue to be accepted; primary keys are accepted whatever their key flags say, since a primary key is certification-capable by construction and certificates carrying no key flags subpacket at all are common. Third-party revocations are deliberately outside the rule, since declining to honour one would keep trust alive rather than withdraw it.","status":"published","published":"2026-10-03T08:46:33.868Z","modified":"2026-10-05T16:03:23.403Z","cvss":[{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/U:Amber","level":"high","assessor":"cna"}],"cwes":["CWE-863","CWE-285"],"updated_at":"2026-11-02T14:19:49.199185Z"}],"euvd":[{"id":"EUVD-2026-92002","description":"In Bouncy Castle for Java before 1.86, the high-level OpenPGP certificate API accepted a third-party certification or trust delegation from any component key of the issuing certificate, without requiring that component to have been granted the authority to certify. OpenPGPCertificate.getCertificationBy() and getDelegationBy() resolve a third-party signature by matching its issuer key identifier against every key of the third-party certificate, then verify the issuing component's binding chain and the signature itself; nothing checked that the issuing component carried the RFC 9580 sec. 5.2.3.29 certification key flag (CERTIFY_OTHER) when the signature was created. A subkey bound only with SIGN_DATA - the online signing subkey of exactly the offline-primary arrangement those key flags exist to express - could therefore issue a positive User ID certification over an attacker-controlled identity, or a full-trust depth-one direct-key delegation of introducer trust, and the API returned it as a valid signature chain attributed to the third-party certificate. An application treating getCertificationBy(...).isValid() or getDelegationBy(...) as an identity or trusted-introducer decision would attribute the attacker's assertion to the offline primary key. The same held for a legacy RSA subkey bound only for encryption, whose algorithm is nonetheless able to sign. This does not forge the primary key's signature or recover any private key; it promotes an already-compromised restricted subkey to the primary key's identity-issuing authority, defeating the containment the key-flag separation provides. A third-party certification or delegation is now attributed to the issuing certificate only when the component key that made it is the primary key, or is a subkey holding CERTIFY_OTHER when the signature was created, so certification-capable subkeys continue to be accepted; primary keys are accepted whatever their key flags say, since a primary key is certification-capable by construction and certificates carrying no key flags subpacket at all are common. Third-party revocations are deliberately outside the rule, since declining to honour one would keep trust alive rather than withdraw it.","status":"published","published":"2026-10-03T08:46:33Z","modified":"2026-10-05T16:03:23Z","cvss":[{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/U:Amber","level":"high"}],"updated_at":"2026-11-02T17:27:39.819382Z"}],"ghsa":[{"id":"GHSA-7hrr-mw36-px4x","title":"In Bouncy Castle for Java before 1.86, the high-level OpenPGP certificate API accepted a third...","description":"In Bouncy Castle for Java before 1.86, the high-level OpenPGP certificate API accepted a third-party certification or trust delegation from any component key of the issuing certificate, without requiring that component to have been granted the authority to certify. OpenPGPCertificate.getCertificationBy() and getDelegationBy() resolve a third-party signature by matching its issuer key identifier against every key of the third-party certificate, then verify the issuing component's binding chain and the signature itself; nothing checked that the issuing component carried the RFC 9580 sec. 5.2.3.29 certification key flag (CERTIFY_OTHER) when the signature was created. A subkey bound only with SIGN_DATA - the online signing subkey of exactly the offline-primary arrangement those key flags exist to express - could therefore issue a positive User ID certification over an attacker-controlled identity, or a full-trust depth-one direct-key delegation of introducer trust, and the API returned it as a valid signature chain attributed to the third-party certificate. An application treating getCertificationBy(...).isValid() or getDelegationBy(...) as an identity or trusted-introducer decision would attribute the attacker's assertion to the offline primary key. The same held for a legacy RSA subkey bound only for encryption, whose algorithm is nonetheless able to sign. This does not forge the primary key's signature or recover any private key; it promotes an already-compromised restricted subkey to the primary key's identity-issuing authority, defeating the containment the key-flag separation provides. A third-party certification or delegation is now attributed to the issuing certificate only when the component key that made it is the primary key, or is a subkey holding CERTIFY_OTHER when the signature was created, so certification-capable subkeys continue to be accepted; primary keys are accepted whatever their key flags say, since a primary key is certification-capable by construction and certificates carrying no key flags subpacket at all are common. Third-party revocations are deliberately outside the rule, since declining to honour one would keep trust alive rather than withdraw it.","status":"published","published":"2026-10-03T09:31:18Z","modified":"2026-10-03T09:31:26Z","cvss":[{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber","level":"high"}],"cwes":["CWE-285"],"updated_at":"2026-11-02T15:12:44.85091Z"}],"nvd":[{"id":"CVE-2026-71886","description":"In Bouncy Castle for Java before 1.86, the high-level OpenPGP certificate API accepted a third-party certification or trust delegation from any component key of the issuing certificate, without requiring that component to have been granted the authority to certify. OpenPGPCertificate.getCertificationBy() and getDelegationBy() resolve a third-party signature by matching its issuer key identifier against every key of the third-party certificate, then verify the issuing component's binding chain and the signature itself; nothing checked that the issuing component carried the RFC 9580 sec. 5.2.3.29 certification key flag (CERTIFY_OTHER) when the signature was created. A subkey bound only with SIGN_DATA - the online signing subkey of exactly the offline-primary arrangement those key flags exist to express - could therefore issue a positive User ID certification over an attacker-controlled identity, or a full-trust depth-one direct-key delegation of introducer trust, and the API returned it as a valid signature chain attributed to the third-party certificate. An application treating getCertificationBy(...).isValid() or getDelegationBy(...) as an identity or trusted-introducer decision would attribute the attacker's assertion to the offline primary key. The same held for a legacy RSA subkey bound only for encryption, whose algorithm is nonetheless able to sign. This does not forge the primary key's signature or recover any private key; it promotes an already-compromised restricted subkey to the primary key's identity-issuing authority, defeating the containment the key-flag separation provides. A third-party certification or delegation is now attributed to the issuing certificate only when the component key that made it is the primary key, or is a subkey holding CERTIFY_OTHER when the signature was created, so certification-capable subkeys continue to be accepted; primary keys are accepted whatever their key flags say, since a primary key is certification-capable by construction and certificates carrying no key flags subpacket at all are common. Third-party revocations are deliberately outside the rule, since declining to honour one would keep trust alive rather than withdraw it.","status":"published","published":"2026-10-03T09:17:04.897Z","modified":"2026-10-06T14:49:40.823Z","cvss":[{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber","level":"high","assessor":"secondary"}],"cwes":["CWE-285","CWE-863"],"updated_at":"2026-11-02T14:12:53.75133Z"}],"osv":[{"id":"CVE-2026-71886","title":"OpenPGP certification accepted from a subkey without certification authority","description":"In Bouncy Castle for Java before 1.86, the high-level OpenPGP certificate API accepted a third-party certification or trust delegation from any component key of the issuing certificate, without requiring that component to have been granted the authority to certify. OpenPGPCertificate.getCertificationBy() and getDelegationBy() resolve a third-party signature by matching its issuer key identifier against every key of the third-party certificate, then verify the issuing component's binding chain and the signature itself; nothing checked that the issuing component carried the RFC 9580 sec. 5.2.3.29 certification key flag (CERTIFY_OTHER) when the signature was created. A subkey bound only with SIGN_DATA - the online signing subkey of exactly the offline-primary arrangement those key flags exist to express - could therefore issue a positive User ID certification over an attacker-controlled identity, or a full-trust depth-one direct-key delegation of introducer trust, and the API returned it as a valid signature chain attributed to the third-party certificate. An application treating getCertificationBy(...).isValid() or getDelegationBy(...) as an identity or trusted-introducer decision would attribute the attacker's assertion to the offline primary key. The same held for a legacy RSA subkey bound only for encryption, whose algorithm is nonetheless able to sign. This does not forge the primary key's signature or recover any private key; it promotes an already-compromised restricted subkey to the primary key's identity-issuing authority, defeating the containment the key-flag separation provides. A third-party certification or delegation is now attributed to the issuing certificate only when the component key that made it is the primary key, or is a subkey holding CERTIFY_OTHER when the signature was created, so certification-capable subkeys continue to be accepted; primary keys are accepted whatever their key flags say, since a primary key is certification-capable by construction and certificates carrying no key flags subpacket at all are common. Third-party revocations are deliberately outside the rule, since declining to honour one would keep trust alive rather than withdraw it.","status":"published","published":"2026-10-03T08:46:33.868Z","modified":"2026-11-04T17:27:21.757770451Z","cvss":[{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/U:Amber","level":"high"}],"cwes":["CWE-285","CWE-863"],"updated_at":"2026-11-04T17:42:10.252324Z"},{"id":"DEBIAN-CVE-2026-71886","description":"In Bouncy Castle for Java before 1.86, the high-level OpenPGP certificate API accepted a third-party certification or trust delegation from any component key of the issuing certificate, without requiring that component to have been granted the authority to certify. OpenPGPCertificate.getCertificationBy() and getDelegationBy() resolve a third-party signature by matching its issuer key identifier against every key of the third-party certificate, then verify the issuing component's binding chain and the signature itself; nothing checked that the issuing component carried the RFC 9580 sec. 5.2.3.29 certification key flag (CERTIFY_OTHER) when the signature was created. A subkey bound only with SIGN_DATA - the online signing subkey of exactly the offline-primary arrangement those key flags exist to express - could therefore issue a positive User ID certification over an attacker-controlled identity, or a full-trust depth-one direct-key delegation of introducer trust, and the API returned it as a valid signature chain attributed to the third-party certificate. An application treating getCertificationBy(...).isValid() or getDelegationBy(...) as an identity or trusted-introducer decision would attribute the attacker's assertion to the offline primary key. The same held for a legacy RSA subkey bound only for encryption, whose algorithm is nonetheless able to sign. This does not forge the primary key's signature or recover any private key; it promotes an already-compromised restricted subkey to the primary key's identity-issuing authority, defeating the containment the key-flag separation provides. A third-party certification or delegation is now attributed to the issuing certificate only when the component key that made it is the primary key, or is a subkey holding CERTIFY_OTHER when the signature was created, so certification-capable subkeys continue to be accepted; primary keys are accepted whatever their key flags say, since a primary key is certification-capable by construction and certificates carrying no key flags subpacket at all are common. Third-party revocations are deliberately outside the rule, since declining to honour one would keep trust alive rather than withdraw it.","status":"published","published":"2026-10-03T09:17:04.897Z","modified":"2026-10-07T09:47:34.259863466Z","cvss":[{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber","level":"high"}],"updated_at":"2026-11-02T15:46:02.094661Z"},{"id":"UBUNTU-CVE-2026-71886","description":"In Bouncy Castle for Java before 1.86, the high-level OpenPGP certificate API accepted a third-party certification or trust delegation from any component key of the issuing certificate, without requiring that component to have been granted the authority to certify. OpenPGPCertificate.getCertificationBy() and getDelegationBy() resolve a third-party signature by matching its issuer key identifier against every key of the third-party certificate, then verify the issuing component's binding chain and the signature itself; nothing checked that the issuing component carried the RFC 9580 sec. 5.2.3.29 certification key flag (CERTIFY_OTHER) when the signature was created. A subkey bound only with SIGN_DATA - the online signing subkey of exactly the offline-primary arrangement those key flags exist to express - could therefore issue a positive User ID certification over an attacker-controlled identity, or a full-trust depth-one direct-key delegation of introducer trust, and the API returned it as a valid signature chain attributed to the third-party certificate. An application treating getCertificationBy(...).isValid() or getDelegationBy(...) as an identity or trusted-introducer decision would attribute the attacker's assertion to the offline primary key. The same held for a legacy RSA subkey bound only for encryption, whose algorithm is nonetheless able to sign. This does not forge the primary key's signature or recover any private key; it promotes an already-compromised restricted subkey to the primary key's identity-issuing authority, defeating the containment the key-flag separation provides. A third-party certification or delegation is now attributed to the issuing certificate only when the component key that made it is the primary key, or is a subkey holding CERTIFY_OTHER when the signature was created, so certification-capable subkeys continue to be accepted; primary keys are accepted whatever their key flags say, since a primary key is certification-capable by construction and certificates carrying no key flags subpacket at all are common. Third-party revocations are deliberately outside the rule, since declining to honour one would keep trust alive rather than withdraw it.","status":"published","published":"2026-10-03T09:17:00Z","modified":"2026-10-17T12:59:33.316568514Z","cvss":[{"version":"4.0","score":8.2,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/U:Amber","level":"high"}],"updated_at":"2026-11-02T16:57:03.035847Z"},{"id":"openSUSE-SU-2026:12090-1","title":"bouncycastle-1.86-1.1 on GA media","description":"These are all security issues fixed in the bouncycastle-1.86-1.1 package on the GA media of openSUSE Tumbleweed.","status":"published","published":"2026-10-09T00:00:00Z","modified":"2026-10-10T17:23:22.29222791Z","updated_at":"2026-11-02T16:58:40.245664Z"},{"id":"openSUSE-SU-2026:22169-1","title":"Security update for bouncycastle","description":"This update for bouncycastle fixes the following issues:\n\nUpdate to 1.86:\n\n- CVE-2026-17507: negative signed leaf_index values from unsigned wire encodings can cause heap exhaustion\n  (bsc#1284075).\n- CVE-2026-17508: unbounded KDF iteration and memory parameters can cause resource exhaustion (bsc#1284073).\n- CVE-2026-18036: variable-time modulo and division operations in NTRU implementation can allow timing side-channel\n  attacks (bsc#1284065).\n- CVE-2026-18040: table lookups and variable-time duplicate scanning in HQC can cause cache side-channel leaks\n  (bsc#1284205).\n- CVE-2026-71885: unbound X.509 certificates in MLS LeafNode verification can cause identity impersonation and group\n  message interception (bsc#1284165).\n- CVE-2026-71886: unvalidated CERTIFY_OTHER flags in OpenPGP subkeys can cause unauthorized trust delegations and\n  identity spoofing (bsc#1284212).\n- CVE-2026-71887: missing primary key back-signature validation on subkeys can cause signature misattribution and trust\n  context spoofing (bsc#1284213).\n- CVE-2026-71888: disagreement between digestAlgorithm and authAttrs in CMS parsing can cause unauthenticated attribute\n  injection (bsc#1284215).\n- CVE-2026-71889: skipped leaf certificate evaluation in checkNameConstraints can cause X.509 name constraint bypasses\n  (bsc#1284218).\n- CVE-2026-71890: unbounded Remove proposals in external MLS commits can cause arbitrary group member eviction and\n  session takeover (bsc#1284219).\n- CVE-2026-71891: forged ECPoint curves in BLS12-381 key validation can cause aggregate signature verification bypasses\n  (bsc#1284220).\n- CVE-2026-71892: type mismatch in CMS key-transport validation can cause key-size enforcement bypasses for HKDF-derived\n  content keys (bsc#1284221).\n- CVE-2026-85515: laundered EOF exceptions in OpenPGP message stream processing can cause unregistered truncation errors\n  and integrity check bypasses (bsc#1284222).\n- CVE-2026-97873: unbounded iteration counts in legacy PBES1 and PKCS#12 PBE implementations can cause resource\n  exhaustion (bsc#1284224).\n","status":"published","published":"2026-10-26T13:05:47Z","modified":"2026-11-01T17:23:28.414155623Z","updated_at":"2026-11-02T16:58:42.426393Z"},{"id":"SUSE-SU-2026:24461-1","title":"Security update for bouncycastle","description":"This update for bouncycastle fixes the following issues:\n\nUpdate to 1.86:\n\n- CVE-2026-17507: negative signed leaf_index values from unsigned wire encodings can cause heap exhaustion\n  (bsc#1284075).\n- CVE-2026-17508: unbounded KDF iteration and memory parameters can cause resource exhaustion (bsc#1284073).\n- CVE-2026-18036: variable-time modulo and division operations in NTRU implementation can allow timing side-channel\n  attacks (bsc#1284065).\n- CVE-2026-18040: table lookups and variable-time duplicate scanning in HQC can cause cache side-channel leaks\n  (bsc#1284205).\n- CVE-2026-71885: unbound X.509 certificates in MLS LeafNode verification can cause identity impersonation and group\n  message interception (bsc#1284165).\n- CVE-2026-71886: unvalidated CERTIFY_OTHER flags in OpenPGP subkeys can cause unauthorized trust delegations and\n  identity spoofing (bsc#1284212).\n- CVE-2026-71887: missing primary key back-signature validation on subkeys can cause signature misattribution and trust\n  context spoofing (bsc#1284213).\n- CVE-2026-71888: disagreement between digestAlgorithm and authAttrs in CMS parsing can cause unauthenticated attribute\n  injection (bsc#1284215).\n- CVE-2026-71889: skipped leaf certificate evaluation in checkNameConstraints can cause X.509 name constraint bypasses\n  (bsc#1284218).\n- CVE-2026-71890: unbounded Remove proposals in external MLS commits can cause arbitrary group member eviction and\n  session takeover (bsc#1284219).\n- CVE-2026-71891: forged ECPoint curves in BLS12-381 key validation can cause aggregate signature verification bypasses\n  (bsc#1284220).\n- CVE-2026-71892: type mismatch in CMS key-transport validation can cause key-size enforcement bypasses for HKDF-derived\n  content keys (bsc#1284221).\n- CVE-2026-85515: laundered EOF exceptions in OpenPGP message stream processing can cause unregistered truncation errors\n  and integrity check bypasses (bsc#1284222).\n- CVE-2026-97873: unbounded iteration counts in legacy PBES1 and PKCS#12 PBE implementations can cause resource\n  exhaustion (bsc#1284224).\n","status":"published","published":"2026-10-26T13:14:44Z","modified":"2026-11-04T17:23:17.638528053Z","updated_at":"2026-11-04T17:43:22.558805Z"},{"id":"SUSE-SU-2026:4797-1","title":"Security update for bouncycastle","description":"This update for bouncycastle fixes the following issues:\n\n- CVE-2026-17507: negative signed leaf_index values from unsigned wire encodings can cause heap exhaustion\n  (bsc#1284075).\n- CVE-2026-17508: unbounded KDF iteration and memory parameters can cause resource exhaustion (bsc#1284073).\n- CVE-2026-18036: variable-time modulo and division operations in NTRU implementation can allow timing side-channel\n  attacks (bsc#1284065).\n- CVE-2026-18040: table lookups and variable-time duplicate scanning in HQC can cause cache side-channel leaks\n  (bsc#1284205).\n- CVE-2026-71885: unbound X.509 certificates in MLS LeafNode verification can cause identity impersonation and group\n  message interception (bsc#1284165).\n- CVE-2026-71886: unvalidated CERTIFY_OTHER flags in OpenPGP subkeys can cause unauthorized trust delegations and\n  identity spoofing (bsc#1284212).\n- CVE-2026-71887: missing primary key back-signature validation on subkeys can cause signature misattribution and trust\n  context spoofing (bsc#1284213).\n- CVE-2026-71888: disagreement between digestAlgorithm and authAttrs in CMS parsing can cause unauthenticated attribute\n  injection (bsc#1284215).\n- CVE-2026-71889: skipped leaf certificate evaluation in checkNameConstraints can cause X.509 name constraint bypasses\n  (bsc#1284218).\n- CVE-2026-71890: unbounded Remove proposals in external MLS commits can cause arbitrary group member eviction and\n  session takeover (bsc#1284219).\n- CVE-2026-71891: forged ECPoint curves in BLS12-381 key validation can cause aggregate signature verification bypasses\n  (bsc#1284220).\n- CVE-2026-71892: type mismatch in CMS key-transport validation can cause key-size enforcement bypasses for HKDF-derived\n  content keys (bsc#1284221).\n- CVE-2026-85515: laundered EOF exceptions in OpenPGP message stream processing can cause unregistered truncation errors\n  and integrity check bypasses (bsc#1284222).\n- CVE-2026-97873: unbounded iteration counts in legacy PBES1 and PKCS#12 PBE implementations can cause resource\n  exhaustion (bsc#1284224).\n\nChanges for bouncycastle:\n\n- Updated to version 1.86.\n","status":"published","published":"2026-10-21T07:54:59Z","modified":"2026-10-21T20:02:15.286117133Z","updated_at":"2026-11-02T15:54:05.838224Z"}]}}