{"id":"CVE-2026-123594","aliases":["AZL-113200","DEBIAN-CVE-2026-123594","EUVD-2026-119353","GHSA-86vr-jm6c-7cpg","GHSA-fg2p-gxqh-hm83","RUSTSEC-2026-0511","RUSTSEC-2026-0519","UBUNTU-CVE-2026-123594"],"status":"published","title":"Hickory DNS through 0.26.0-alpha.1 DNSSEC NSEC Validation Bypass for Empty Non-Terminals","description":"Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain an NSEC validation flaw that returns a secure proof for NXDOMAIN responses when the covering NSEC's Next Domain Name is a strict descendant of the query name, which actually proves the name exists as an empty non-terminal. On-path attackers can flip the unsigned rcode of a genuine signed NODATA response from NOERROR to NXDOMAIN, causing validators to accept forged nonexistence of the name.","severity":{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.0012,"percentile":0.01828,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-345"],"published":"2026-09-03T12:00:00Z","modified":"2026-11-12T14:40:42Z","fixes":[{"ecosystem":"Debian:14","package":"rust-hickory-net","fixed_in":["0.26.3-1"],"sources":["osv"]},{"ecosystem":"crates.io","package":"hickory-proto","fixed_in":["0.26.0-beta.1"],"sources":["osv"]},{"ecosystem":"crates.io","package":"hickory-net","fixed_in":["0.26.2"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Azure Linux:3","package":"netavark","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"1.10.3-9"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"rust-hickory-net","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.26.3-1"}]}],"versions":["0.26.1-1","0.26.1-2"]},{"source":"osv","ecosystem":"Debian:13","package":"rust-hickory-proto","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.24.4-2","0.24.4-3","0.24.4-4","0.24.4-4.1","0.24.4-5","0.24.4-6","0.25.2-1","0.25.2-2","0.25.2-3","0.26.1-1","0.26.3-1"]},{"source":"osv","ecosystem":"Debian:14","package":"rust-hickory-proto","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.24.4-2","0.24.4-3","0.24.4-4","0.24.4-4.1","0.24.4-5","0.24.4-6","0.25.2-1","0.25.2-2","0.25.2-3","0.26.1-1","0.26.3-1"]},{"source":"osv","ecosystem":"crates.io","package":"hickory-proto","ranges":[{"type":"SEMVER","events":[{"introduced":"0.0.0-0"},{"fixed":"0.26.0-beta.1"}]}]},{"source":"osv","ecosystem":"crates.io","package":"hickory-net","ranges":[{"type":"SEMVER","events":[{"introduced":"0.0.0-0"},{"fixed":"0.26.2"}]}]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"rust-hickory-proto","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.24.0-1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"rust-hickory-net","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.26.1-1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"rust-hickory-proto","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.24.4-6","0.26.1-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"rust-hickory-proto","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.24.4-4.1","0.24.4-6"]}],"products":[{"vendor":"hickory-dns","product":"hickory-dns"}],"references":[{"url":"https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-86vr-jm6c-7cpg","tags":["vendor-advisory","advisory","report"]},{"url":"https://www.vulncheck.com/advisories/hickory-dns-through-0.26.0-alpha.1-dnssec-nsec-validation-bypass-for-empty-non-terminals","tags":["third-party-advisory","advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-123594","tags":["web","advisory"]},{"url":"https://github.com/advisories/GHSA-fg2p-gxqh-hm83"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/123xxx/CVE-2026-123594.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-123594","tags":["advisory"]},{"url":"https://crates.io/crates/hickory-proto","tags":["package"]},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0511.html","tags":["advisory"]},{"url":"https://github.com/hickory-dns/hickory-dns/commit/bfbe7ede4021965526f065be9b415945ce575e29","tags":["web"]},{"url":"https://crates.io/crates/hickory-net","tags":["package"]},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0519.html","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-123594","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-123594","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-123594","title":"Hickory DNS through 0.26.0-alpha.1 DNSSEC NSEC Validation Bypass for Empty Non-Terminals","description":"Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain an NSEC validation flaw that returns a secure proof for NXDOMAIN responses when the covering NSEC's Next Domain Name is a strict descendant of the query name, which actually proves the name exists as an empty non-terminal. On-path attackers can flip the unsigned rcode of a genuine signed NODATA response from NOERROR to NXDOMAIN, causing validators to accept forged nonexistence of the name.","status":"published","published":"2026-11-08T01:38:24.397Z","modified":"2026-11-09T13:51:34.546Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"},{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-345"],"updated_at":"2026-11-08T02:36:49.037074Z"}],"euvd":[{"id":"EUVD-2026-119353","description":"Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain an NSEC validation flaw that returns a secure proof for NXDOMAIN responses when the covering NSEC's Next Domain Name is a strict descendant of the query name, which actually proves the name exists as an empty non-terminal. On-path attackers can flip the unsigned rcode of a genuine signed NODATA response from NOERROR to NXDOMAIN, causing validators to accept forged nonexistence of the name.","status":"published","published":"2026-11-08T01:38:24Z","modified":"2026-11-09T13:51:34Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-08T06:12:04.155226Z"}],"ghsa":[{"id":"GHSA-fg2p-gxqh-hm83","title":"Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2...","description":"Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain an NSEC validation flaw that returns a secure proof for NXDOMAIN responses when the covering NSEC's Next Domain Name is a strict descendant of the query name, which actually proves the name exists as an empty non-terminal. On-path attackers can flip the unsigned rcode of a genuine signed NODATA response from NOERROR to NXDOMAIN, causing validators to accept forged nonexistence of the name.","status":"published","published":"2026-11-08T03:30:35Z","modified":"2026-11-08T03:30:36Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/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:X","level":"medium"},{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium"}],"cwes":["CWE-345"],"updated_at":"2026-11-08T03:41:53.166172Z"}],"nvd":[{"id":"CVE-2026-123594","description":"Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain an NSEC validation flaw that returns a secure proof for NXDOMAIN responses when the covering NSEC's Next Domain Name is a strict descendant of the query name, which actually proves the name exists as an empty non-terminal. On-path attackers can flip the unsigned rcode of a genuine signed NODATA response from NOERROR to NXDOMAIN, causing validators to accept forged nonexistence of the name.","status":"published","published":"2026-11-08T02:16:53.71Z","modified":"2026-11-10T22:15:59.797Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/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:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-345"],"updated_at":"2026-11-09T16:14:55.503615Z"}],"osv":[{"id":"CVE-2026-123594","title":"Hickory DNS through 0.26.0-alpha.1 DNSSEC NSEC Validation Bypass for Empty Non-Terminals","description":"Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain an NSEC validation flaw that returns a secure proof for NXDOMAIN responses when the covering NSEC's Next Domain Name is a strict descendant of the query name, which actually proves the name exists as an empty non-terminal. On-path attackers can flip the unsigned rcode of a genuine signed NODATA response from NOERROR to NXDOMAIN, causing validators to accept forged nonexistence of the name.","status":"published","published":"2026-11-08T01:38:24.397Z","modified":"2026-11-12T14:40:42.050905197Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-345"],"updated_at":"2026-11-12T14:53:10.251383Z"},{"id":"DEBIAN-CVE-2026-123594","description":"Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain an NSEC validation flaw that returns a secure proof for NXDOMAIN responses when the covering NSEC's Next Domain Name is a strict descendant of the query name, which actually proves the name exists as an empty non-terminal. On-path attackers can flip the unsigned rcode of a genuine signed NODATA response from NOERROR to NXDOMAIN, causing validators to accept forged nonexistence of the name.","status":"published","published":"2026-11-08T02:16:53.71Z","modified":"2026-11-11T09:47:36.486030322Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/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:X","level":"medium"}],"updated_at":"2026-11-10T10:26:30.347596Z"},{"id":"UBUNTU-CVE-2026-123594","description":"Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain an NSEC validation flaw that returns a secure proof for NXDOMAIN responses when the covering NSEC's Next Domain Name is a strict descendant of the query name, which actually proves the name exists as an empty non-terminal. On-path attackers can flip the unsigned rcode of a genuine signed NODATA response from NOERROR to NXDOMAIN, causing validators to accept forged nonexistence of the name.","status":"published","published":"2026-11-09T00:00:00Z","modified":"2026-11-10T02:50:13.554033068Z","cvss":[{"version":"3.1","score":4.8,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L","level":"medium"},{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-10T03:18:58.105788Z"},{"id":"AZL-113200","title":"CVE-2026-123594 affecting package netavark 1.10.3-9","description":"Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain an NSEC validation flaw that returns a secure proof for NXDOMAIN responses when the covering NSEC's Next Domain Name is a strict descendant of the query name, which actually proves the name exists as an empty non-terminal. On-path attackers can flip the unsigned rcode of a genuine signed NODATA response from NOERROR to NXDOMAIN, causing validators to accept forged nonexistence of the name.","status":"published","published":"2026-11-08T02:16:53Z","modified":"2026-11-11T14:17:32.586141324Z","updated_at":"2026-11-11T14:42:54.020399Z"},{"id":"RUSTSEC-2026-0511","title":"NXDOMAIN accepted for a proven empty non-terminal (hickory-proto)","description":"Up to 0.26.0-alpha.1, hickory-proto's NSEC validation accepted an NXDOMAIN response as secure even when the covering NSEC record's next domain name was below the queried name, which proves the name exists as an empty non-terminal. Because the response code is not signed, someone who can modify DNS responses could turn a genuine signed NODATA response into an accepted NXDOMAIN.\n\nFrom 0.26.0-beta.1 the DNSSEC validation code lives in the hickory-net crate, where this was fixed in hickory-net 0.26.2. No hickory-proto release contains a fix. Users of DNSSEC validation in older hickory-proto releases (directly or through hickory-resolver or hickory-recursor) should move to the 0.26.2 or later releases, which validate through hickory-net.","status":"published","published":"2026-09-03T12:00:00Z","modified":"2026-11-12T14:40:42.050905197Z","updated_at":"2026-11-12T14:53:10.251383Z"},{"id":"RUSTSEC-2026-0519","title":"NXDOMAIN accepted for an empty non-terminal that the NSEC record proves exists","description":"When an NSEC record's next domain name is below the queried name, the queried name exists as an empty non-terminal (RFC 8020 section 3.1). The NSEC validator did not check for this case and accepted an NXDOMAIN response backed by such a record as secure.\n\nThe response code is not covered by any signature. An attacker who can modify DNS responses can take a genuine signed NODATA response for an empty non-terminal, change its response code to NXDOMAIN, and have the validator accept that an existing name does not exist.\n\nThis affects DNSSEC validation through `DnssecDnsHandle` when built with `dnssec-ring` or `dnssec-aws-lc-rs`.\n\nThe fix rejects NXDOMAIN as bogus, and validates NODATA as secure, when the covering NSEC record's next domain name is below the queried name and is not the zone apex. It is in 0.26.2.","status":"published","published":"2026-09-03T12:00:00Z","modified":"2026-11-12T14:40:42.050905197Z","updated_at":"2026-11-12T14:53:10.251383Z"}]}}