{"id":"CVE-2026-71892","aliases":["DEBIAN-CVE-2026-71892","EUVD-2026-91989","GHSA-x42w-4gqh-qrvm","SUSE-SU-2026:24461-1","SUSE-SU-2026:4797-1","UBUNTU-CVE-2026-71892","openSUSE-SU-2026:12090-1","openSUSE-SU-2026:22169-1"],"status":"published","title":"CMS key-transport recipient key-size validation never runs for RFC 9709 HKDF-derived keys","description":"In Bouncy Castle for Java before 1.86, the opt-in key-size validation on CMS key-transport recipients, org.bouncycastle.cms.jcajce.JceKeyTransRecipient.setKeySizeValidation(true), never ran for a message using RFC 9709 content-encryption key derivation (id-alg-cek-hkdf-sha256). The branch that should have selected the actual content-encryption algorithm carried in the key derivation AlgorithmIdentifier's parameters compared the encrypted-key byte array against the id-alg-cek-hkdf-sha256 object identifier, a comparison between a byte array and an ASN1ObjectIdentifier that is false for every possible input, so the check fell through to a key-size lookup on the outer wrapper OID. That OID identifies a key-derivation construction rather than a cipher and has no registered key size, so the size comparison was skipped entirely. A key-transport EnvelopedData or AuthEnvelopedData whose transported, HKDF-derived content-encryption key did not match the key size of the advertised content-encryption algorithm was therefore accepted even with validation explicitly enabled, silently defeating the only mechanism the API offers for enforcing recovered key size. The recipient now dispatches on the content-encryption AlgorithmIdentifier's algorithm OID, so validation checks the recovered key against the inner content-encryption algorithm. Messages with a matching key size, non-HKDF messages, and recipients that do not enable validation are unaffected. This issue also affects Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series).","severity":{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/U:Amber","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00173,"percentile":0.06776,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-697"],"published":"2026-10-03T08:30:26Z","modified":"2026-11-04T17:27:19Z","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-fja"},{"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%9071892","tags":["vendor-advisory","advisory","report"]},{"url":"https://github.com/bcgit/bc-java/commit/be0a7d925c818ef2f338bcec55178b9b6336dfc3","tags":["patch","fix","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-71892","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-x42w-4gqh-qrvm"},{"url":"https://www.bouncycastle.org/download/bouncy-castle-java-fips/","tags":["web"]},{"url":"https://www.bouncycastle.org/download/bouncy-castle-java/","tags":["web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/71xxx/CVE-2026-71892.json","tags":["advisory"]},{"url":"https://github.com/bcgit/bc-java","tags":["package"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-71892","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-2026-71892","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-71892","tags":["report"]},{"url":"","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-71892","title":"CMS key-transport recipient key-size validation never runs for RFC 9709 HKDF-derived keys","description":"In Bouncy Castle for Java before 1.86, the opt-in key-size validation on CMS key-transport recipients, org.bouncycastle.cms.jcajce.JceKeyTransRecipient.setKeySizeValidation(true), never ran for a message using RFC 9709 content-encryption key derivation (id-alg-cek-hkdf-sha256). The branch that should have selected the actual content-encryption algorithm carried in the key derivation AlgorithmIdentifier's parameters compared the encrypted-key byte array against the id-alg-cek-hkdf-sha256 object identifier, a comparison between a byte array and an ASN1ObjectIdentifier that is false for every possible input, so the check fell through to a key-size lookup on the outer wrapper OID. That OID identifies a key-derivation construction rather than a cipher and has no registered key size, so the size comparison was skipped entirely. A key-transport EnvelopedData or AuthEnvelopedData whose transported, HKDF-derived content-encryption key did not match the key size of the advertised content-encryption algorithm was therefore accepted even with validation explicitly enabled, silently defeating the only mechanism the API offers for enforcing recovered key size. The recipient now dispatches on the content-encryption AlgorithmIdentifier's algorithm OID, so validation checks the recovered key against the inner content-encryption algorithm. Messages with a matching key size, non-HKDF messages, and recipients that do not enable validation are unaffected. This issue also affects Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series).","status":"published","published":"2026-10-03T08:30:26.982Z","modified":"2026-10-05T16:58:40.411Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/U:Amber","level":"medium","assessor":"cna"}],"cwes":["CWE-697"],"updated_at":"2026-11-02T14:19:49.199185Z"}],"euvd":[{"id":"EUVD-2026-91989","description":"In Bouncy Castle for Java before 1.86, the opt-in key-size validation on CMS key-transport recipients, org.bouncycastle.cms.jcajce.JceKeyTransRecipient.setKeySizeValidation(true), never ran for a message using RFC 9709 content-encryption key derivation (id-alg-cek-hkdf-sha256). The branch that should have selected the actual content-encryption algorithm carried in the key derivation AlgorithmIdentifier's parameters compared the encrypted-key byte array against the id-alg-cek-hkdf-sha256 object identifier, a comparison between a byte array and an ASN1ObjectIdentifier that is false for every possible input, so the check fell through to a key-size lookup on the outer wrapper OID. That OID identifies a key-derivation construction rather than a cipher and has no registered key size, so the size comparison was skipped entirely. A key-transport EnvelopedData or AuthEnvelopedData whose transported, HKDF-derived content-encryption key did not match the key size of the advertised content-encryption algorithm was therefore accepted even with validation explicitly enabled, silently defeating the only mechanism the API offers for enforcing recovered key size. The recipient now dispatches on the content-encryption AlgorithmIdentifier's algorithm OID, so validation checks the recovered key against the inner content-encryption algorithm. Messages with a matching key size, non-HKDF messages, and recipients that do not enable validation are unaffected. This issue also affects Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series).","status":"published","published":"2026-10-03T08:30:26Z","modified":"2026-10-05T16:58:40Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/U:Amber","level":"medium"}],"updated_at":"2026-11-02T17:27:39.384414Z"}],"ghsa":[{"id":"GHSA-x42w-4gqh-qrvm","title":"In Bouncy Castle for Java before 1.86, the opt-in key-size validation on CMS key-transport...","description":"In Bouncy Castle for Java before 1.86, the opt-in key-size validation on CMS key-transport recipients, org.bouncycastle.cms.jcajce.JceKeyTransRecipient.setKeySizeValidation(true), never ran for a message using RFC 9709 content-encryption key derivation (id-alg-cek-hkdf-sha256). The branch that should have selected the actual content-encryption algorithm carried in the key derivation AlgorithmIdentifier's parameters compared the encrypted-key byte array against the id-alg-cek-hkdf-sha256 object identifier, a comparison between a byte array and an ASN1ObjectIdentifier that is false for every possible input, so the check fell through to a key-size lookup on the outer wrapper OID. That OID identifies a key-derivation construction rather than a cipher and has no registered key size, so the size comparison was skipped entirely. A key-transport EnvelopedData or AuthEnvelopedData whose transported, HKDF-derived content-encryption key did not match the key size of the advertised content-encryption algorithm was therefore accepted even with validation explicitly enabled, silently defeating the only mechanism the API offers for enforcing recovered key size. The recipient now dispatches on the content-encryption AlgorithmIdentifier's algorithm OID, so validation checks the recovered key against the inner content-encryption algorithm. Messages with a matching key size, non-HKDF messages, and recipients that do not enable validation are unaffected. This issue also affects Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series).","status":"published","published":"2026-10-03T09:31:18Z","modified":"2026-10-03T09:31:26Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/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":"medium"}],"cwes":["CWE-697"],"updated_at":"2026-11-02T15:12:44.85091Z"}],"nvd":[{"id":"CVE-2026-71892","description":"In Bouncy Castle for Java before 1.86, the opt-in key-size validation on CMS key-transport recipients, org.bouncycastle.cms.jcajce.JceKeyTransRecipient.setKeySizeValidation(true), never ran for a message using RFC 9709 content-encryption key derivation (id-alg-cek-hkdf-sha256). The branch that should have selected the actual content-encryption algorithm carried in the key derivation AlgorithmIdentifier's parameters compared the encrypted-key byte array against the id-alg-cek-hkdf-sha256 object identifier, a comparison between a byte array and an ASN1ObjectIdentifier that is false for every possible input, so the check fell through to a key-size lookup on the outer wrapper OID. That OID identifies a key-derivation construction rather than a cipher and has no registered key size, so the size comparison was skipped entirely. A key-transport EnvelopedData or AuthEnvelopedData whose transported, HKDF-derived content-encryption key did not match the key size of the advertised content-encryption algorithm was therefore accepted even with validation explicitly enabled, silently defeating the only mechanism the API offers for enforcing recovered key size. The recipient now dispatches on the content-encryption AlgorithmIdentifier's algorithm OID, so validation checks the recovered key against the inner content-encryption algorithm. Messages with a matching key size, non-HKDF messages, and recipients that do not enable validation are unaffected. This issue also affects Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series).","status":"published","published":"2026-10-03T09:17:05.913Z","modified":"2026-10-06T14:49:40.823Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/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":"medium","assessor":"secondary"}],"cwes":["CWE-697"],"updated_at":"2026-11-02T14:12:53.75133Z"}],"osv":[{"id":"CVE-2026-71892","title":"CMS key-transport recipient key-size validation never runs for RFC 9709 HKDF-derived keys","description":"In Bouncy Castle for Java before 1.86, the opt-in key-size validation on CMS key-transport recipients, org.bouncycastle.cms.jcajce.JceKeyTransRecipient.setKeySizeValidation(true), never ran for a message using RFC 9709 content-encryption key derivation (id-alg-cek-hkdf-sha256). The branch that should have selected the actual content-encryption algorithm carried in the key derivation AlgorithmIdentifier's parameters compared the encrypted-key byte array against the id-alg-cek-hkdf-sha256 object identifier, a comparison between a byte array and an ASN1ObjectIdentifier that is false for every possible input, so the check fell through to a key-size lookup on the outer wrapper OID. That OID identifies a key-derivation construction rather than a cipher and has no registered key size, so the size comparison was skipped entirely. A key-transport EnvelopedData or AuthEnvelopedData whose transported, HKDF-derived content-encryption key did not match the key size of the advertised content-encryption algorithm was therefore accepted even with validation explicitly enabled, silently defeating the only mechanism the API offers for enforcing recovered key size. The recipient now dispatches on the content-encryption AlgorithmIdentifier's algorithm OID, so validation checks the recovered key against the inner content-encryption algorithm. Messages with a matching key size, non-HKDF messages, and recipients that do not enable validation are unaffected. This issue also affects Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series).","status":"published","published":"2026-10-03T08:30:26.982Z","modified":"2026-11-04T17:27:19.666386797Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/U:Amber","level":"medium"}],"cwes":["CWE-697"],"updated_at":"2026-11-04T17:42:25.015942Z"},{"id":"DEBIAN-CVE-2026-71892","description":"In Bouncy Castle for Java before 1.86, the opt-in key-size validation on CMS key-transport recipients, org.bouncycastle.cms.jcajce.JceKeyTransRecipient.setKeySizeValidation(true), never ran for a message using RFC 9709 content-encryption key derivation (id-alg-cek-hkdf-sha256). The branch that should have selected the actual content-encryption algorithm carried in the key derivation AlgorithmIdentifier's parameters compared the encrypted-key byte array against the id-alg-cek-hkdf-sha256 object identifier, a comparison between a byte array and an ASN1ObjectIdentifier that is false for every possible input, so the check fell through to a key-size lookup on the outer wrapper OID. That OID identifies a key-derivation construction rather than a cipher and has no registered key size, so the size comparison was skipped entirely. A key-transport EnvelopedData or AuthEnvelopedData whose transported, HKDF-derived content-encryption key did not match the key size of the advertised content-encryption algorithm was therefore accepted even with validation explicitly enabled, silently defeating the only mechanism the API offers for enforcing recovered key size. The recipient now dispatches on the content-encryption AlgorithmIdentifier's algorithm OID, so validation checks the recovered key against the inner content-encryption algorithm. Messages with a matching key size, non-HKDF messages, and recipients that do not enable validation are unaffected. This issue also affects Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series).","status":"published","published":"2026-10-03T09:17:05.913Z","modified":"2026-10-07T09:47:32.018170489Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/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":"medium"}],"updated_at":"2026-11-02T15:46:02.094661Z"},{"id":"UBUNTU-CVE-2026-71892","description":"In Bouncy Castle for Java before 1.86, the opt-in key-size validation on CMS key-transport recipients, org.bouncycastle.cms.jcajce.JceKeyTransRecipient.setKeySizeValidation(true), never ran for a message using RFC 9709 content-encryption key derivation (id-alg-cek-hkdf-sha256). The branch that should have selected the actual content-encryption algorithm carried in the key derivation AlgorithmIdentifier's parameters compared the encrypted-key byte array against the id-alg-cek-hkdf-sha256 object identifier, a comparison between a byte array and an ASN1ObjectIdentifier that is false for every possible input, so the check fell through to a key-size lookup on the outer wrapper OID. That OID identifies a key-derivation construction rather than a cipher and has no registered key size, so the size comparison was skipped entirely. A key-transport EnvelopedData or AuthEnvelopedData whose transported, HKDF-derived content-encryption key did not match the key size of the advertised content-encryption algorithm was therefore accepted even with validation explicitly enabled, silently defeating the only mechanism the API offers for enforcing recovered key size. The recipient now dispatches on the content-encryption AlgorithmIdentifier's algorithm OID, so validation checks the recovered key against the inner content-encryption algorithm. Messages with a matching key size, non-HKDF messages, and recipients that do not enable validation are unaffected. This issue also affects Bouncy Castle for Java FIPS (BC-FJA) before bcpkix-fips 2.0.13 (2.0.X series) and 2.1.13 (2.1.X series).","status":"published","published":"2026-10-03T09:17:00Z","modified":"2026-10-17T13:00:47.348333898Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/U:Amber","level":"medium"}],"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"}]}}