{"id":"CVE-2026-123601","aliases":["DEBIAN-CVE-2026-123601","EUVD-2026-119360","GHSA-588m-chg6-8jqj","GHSA-hj9x-wc4q-vmw3","RUSTSEC-2026-0504","RUSTSEC-2026-0506","UBUNTU-CVE-2026-123601"],"status":"published","title":"Hickory DNS 0.26.0-beta.1 before 0.26.2 NSEC3 Proof of Nonexistence Forgery","description":"Hickory DNS hickory-proto 0.25.0 through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 invert the relational operators in the wrap-around branch of find_covering_record() in nsec3.rs, so the last NSEC3 record in a zone's hash ring covers every hash except its owner. Attackers able to inject DNS responses can replay that NSEC3 record and its RRSIG to forge DNSSEC-validated negative responses denying legitimate names.","severity":{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00279,"percentile":0.2067,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-480"],"published":"2026-09-03T12:00:00Z","modified":"2026-11-12T14:10:49Z","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":"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":"0.25.0"},{"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-588m-chg6-8jqj","tags":["vendor-advisory","advisory","report"]},{"url":"https://www.vulncheck.com/advisories/hickory-dns-0.26.0-beta.1-before-0.26.2-nsec3-proof-of-nonexistence-forgery","tags":["third-party-advisory","advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-123601","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-hj9x-wc4q-vmw3"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/123xxx/CVE-2026-123601.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-123601","tags":["advisory"]},{"url":"https://crates.io/crates/hickory-proto","tags":["package"]},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0504.html","tags":["advisory"]},{"url":"https://github.com/hickory-dns/hickory-dns/commit/87ee4f81aa9689d81847770d3a74e13982c9bcdc","tags":["web"]},{"url":"https://crates.io/crates/hickory-net","tags":["package"]},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0506.html","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-123601","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-123601","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-123601","title":"Hickory DNS 0.26.0-beta.1 before 0.26.2 NSEC3 Proof of Nonexistence Forgery","description":"Hickory DNS hickory-proto 0.25.0 through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 invert the relational operators in the wrap-around branch of find_covering_record() in nsec3.rs, so the last NSEC3 record in a zone's hash ring covers every hash except its owner. Attackers able to inject DNS responses can replay that NSEC3 record and its RRSIG to forge DNSSEC-validated negative responses denying legitimate names.","status":"published","published":"2026-11-08T01:38:29.32Z","modified":"2026-11-10T17:57:10.157Z","cvss":[{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-480"],"updated_at":"2026-11-08T02:36:49.037074Z"}],"euvd":[{"id":"EUVD-2026-119360","description":"Hickory DNS hickory-proto 0.25.0 through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 invert the relational operators in the wrap-around branch of find_covering_record() in nsec3.rs, so the last NSEC3 record in a zone's hash ring covers every hash except its owner. Attackers able to inject DNS responses can replay that NSEC3 record and its RRSIG to forge DNSSEC-validated negative responses denying legitimate names.","status":"published","published":"2026-11-08T01:38:29Z","modified":"2026-11-10T17:57:10Z","cvss":[{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-08T06:12:04.155226Z"}],"ghsa":[{"id":"GHSA-hj9x-wc4q-vmw3","title":"Hickory DNS hickory-proto 0.25.0 through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26...","description":"Hickory DNS hickory-proto 0.25.0 through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 invert the relational operators in the wrap-around branch of find_covering_record() in nsec3.rs, so the last NSEC3 record in a zone's hash ring covers every hash except its owner. Attackers able to inject DNS responses can replay that NSEC3 record and its RRSIG to forge DNSSEC-validated negative responses denying legitimate names.","status":"published","published":"2026-11-08T03:30:36Z","modified":"2026-11-08T03:30:44Z","cvss":[{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/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":"high"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H","level":"medium"}],"cwes":["CWE-480"],"updated_at":"2026-11-08T03:41:54.072675Z"}],"nvd":[{"id":"CVE-2026-123601","description":"Hickory DNS hickory-proto 0.25.0 through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 invert the relational operators in the wrap-around branch of find_covering_record() in nsec3.rs, so the last NSEC3 record in a zone's hash ring covers every hash except its owner. Attackers able to inject DNS responses can replay that NSEC3 record and its RRSIG to forge DNSSEC-validated negative responses denying legitimate names.","status":"published","published":"2026-11-08T02:16:54.797Z","modified":"2026-11-10T22:15:59.797Z","cvss":[{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/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":"high","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H","level":"medium","assessor":"secondary"}],"cwes":["CWE-480"],"updated_at":"2026-11-10T20:21:09.207118Z"}],"osv":[{"id":"CVE-2026-123601","title":"Hickory DNS 0.26.0-beta.1 before 0.26.2 NSEC3 Proof of Nonexistence Forgery","description":"Hickory DNS hickory-proto 0.25.0 through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 invert the relational operators in the wrap-around branch of find_covering_record() in nsec3.rs, so the last NSEC3 record in a zone's hash ring covers every hash except its owner. Attackers able to inject DNS responses can replay that NSEC3 record and its RRSIG to forge DNSSEC-validated negative responses denying legitimate names.","status":"published","published":"2026-11-08T01:38:29.32Z","modified":"2026-11-12T14:10:49.81553643Z","cvss":[{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-480"],"updated_at":"2026-11-12T14:22:44.226553Z"},{"id":"DEBIAN-CVE-2026-123601","description":"Hickory DNS hickory-proto 0.25.0 through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 invert the relational operators in the wrap-around branch of find_covering_record() in nsec3.rs, so the last NSEC3 record in a zone's hash ring covers every hash except its owner. Attackers able to inject DNS responses can replay that NSEC3 record and its RRSIG to forge DNSSEC-validated negative responses denying legitimate names.","status":"published","published":"2026-11-08T02:16:54.797Z","modified":"2026-11-11T10:00:54.982635936Z","cvss":[{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/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":"high"}],"updated_at":"2026-11-11T10:35:16.464644Z"},{"id":"UBUNTU-CVE-2026-123601","description":"Hickory DNS hickory-proto 0.25.0 through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 invert the relational operators in the wrap-around branch of find_covering_record() in nsec3.rs, so the last NSEC3 record in a zone's hash ring covers every hash except its owner. Attackers able to inject DNS responses can replay that NSEC3 record and its RRSIG to forge DNSSEC-validated negative responses denying legitimate names.","status":"published","published":"2026-11-09T00:00:00Z","modified":"2026-11-10T02:50:13.589177379Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H","level":"medium"},{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-10T03:18:58.105788Z"},{"id":"RUSTSEC-2026-0504","title":"Inverted NSEC3 comparison in DNSSEC validation (hickory-proto 0.25)","description":"In hickory-proto 0.25.0 through 0.26.0-alpha.1, DNSSEC validation handled the last NSEC3 record of a zone's hash chain with its two comparisons reversed. That record was treated as covering almost every hash it does not cover, so an attacker who can answer or modify DNS responses could replay it, with its RRSIG, to forge proofs that existing names have no records.\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 hickory-proto 0.25 (directly or through hickory-resolver or hickory-recursor 0.25) should move to the 0.26.2 or later releases, which validate through hickory-net.","status":"published","published":"2026-09-03T12:00:00Z","modified":"2026-11-12T14:10:49.81553643Z","updated_at":"2026-11-12T14:22:44.226553Z"},{"id":"RUSTSEC-2026-0506","title":"Inverted NSEC3 comparison lets one record \"prove\" that almost any name does not exist","description":"When DNSSEC validation looks for the NSEC3 record that covers a hashed name, the last record in the zone's hash chain needs special handling, because its next hashed owner name sorts before its own hash. For that record the two comparisons were reversed: it was treated as covering every hash below its owner hash or above its next hash, which is mostly the part of the chain it does not cover.\n\nAn attacker who can answer or modify DNS responses can replay that one signed NSEC3 record, with its RRSIG, from the target zone and use it in forged negative answers. The validator then accepts proof that names which do exist have no records.\n\nThis affects DNSSEC validation through `DnssecDnsHandle` (resolver, recursor and client) when built with `dnssec-ring` or `dnssec-aws-lc-rs`. The same code was in hickory-proto before it moved to hickory-net.\n\nThe fix corrects the comparison in `find_covering_record`. It is in 0.26.2.","status":"published","published":"2026-09-03T12:00:00Z","modified":"2026-11-12T14:10:49.81553643Z","updated_at":"2026-11-12T14:22:44.226553Z"}]}}