{"id":"CVE-2026-123607","aliases":["EUVD-2026-119366","GHSA-3v94-mw7p-v465","GHSA-jvpj-j4xv-2492","RUSTSEC-2026-0118","RUSTSEC-2026-0120","UBUNTU-CVE-2026-123607"],"status":"published","title":"Hickory DNS NSEC3 Closest-Encloser Proof Unbounded Loop Denial of Service","description":"Hickory DNS hickory-proto 0.25.0-alpha.3 through 0.25.2 and hickory-net before 0.26.1 contain an unbounded loop vulnerability in DnssecDnsHandle NSEC3 closest-encloser proof validation when the SOA owner is not an ancestor of the QNAME. Upstream attackers can return NoData or NXDomain responses with a cross-zone SOA record to panic debug builds or exhaust memory in release builds.","severity":{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00343,"percentile":0.28137,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-835"],"published":"2026-05-01T12:00:00Z","modified":"2026-11-10T02:49:53Z","fixes":[{"ecosystem":"crates.io","package":"hickory-net","fixed_in":["0.26.1"],"sources":["ghsa","osv"]},{"ecosystem":"crates.io","package":"hickory-proto","fixed_in":["0.26.0-beta.1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"crates.io","package":"hickory-proto","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.25.0-alpha.3"},{"last_affected":"0.25.2"}]}]},{"source":"ghsa","ecosystem":"crates.io","package":"hickory-net","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.26.0-alpha.1"},{"last_affected":"0.26.0"},{"fixed":"0.26.1"}]}]},{"source":"osv","ecosystem":"crates.io","package":"hickory-proto","ranges":[{"type":"SEMVER","events":[{"introduced":"0.25.0-alpha.3"},{"last_affected":"0.25.2"}]}]},{"source":"osv","ecosystem":"crates.io","package":"hickory-net","ranges":[{"type":"SEMVER","events":[{"introduced":"0.26.0-alpha.1"},{"fixed":"0.26.1"}]}]},{"source":"osv","ecosystem":"crates.io","package":"hickory-proto","ranges":[{"type":"SEMVER","events":[{"introduced":"0.25.0-alpha.3"},{"fixed":"0.26.0-beta.1"}]}]},{"source":"osv","ecosystem":"crates.io","package":"hickory-net","ranges":[{"type":"SEMVER","events":[{"introduced":"0.0.0-0"},{"fixed":"0.26.1"}]}]},{"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-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-3v94-mw7p-v465","tags":["vendor-advisory","advisory","web","report"]},{"url":"https://www.vulncheck.com/advisories/hickory-dns-nsec3-closest-encloser-proof-unbounded-loop-denial-of-service","tags":["third-party-advisory","advisory","report"]},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0118.html","tags":["web","advisory","report"]},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0120.html","tags":["web","advisory"]},{"url":"https://github.com/advisories/GHSA-3v94-mw7p-v465"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-123607","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-jvpj-j4xv-2492"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/123xxx/CVE-2026-123607.json","tags":["advisory"]},{"url":"https://github.com/hickory-dns/hickory-dns","tags":["package"]},{"url":"https://crates.io/crates/hickory-proto","tags":["package"]},{"url":"https://github.com/hickory-dns/hickory-dns/pull/3597","tags":["web"]},{"url":"https://crates.io/crates/hickory-net","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2026-123607","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-123607","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-123607","title":"Hickory DNS NSEC3 Closest-Encloser Proof Unbounded Loop Denial of Service","description":"Hickory DNS hickory-proto 0.25.0-alpha.3 through 0.25.2 and hickory-net before 0.26.1 contain an unbounded loop vulnerability in DnssecDnsHandle NSEC3 closest-encloser proof validation when the SOA owner is not an ancestor of the QNAME. Upstream attackers can return NoData or NXDomain responses with a cross-zone SOA record to panic debug builds or exhaust memory in release builds.","status":"published","published":"2026-11-08T01:38:33.416Z","modified":"2026-11-08T01:38:33.416Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-835"],"updated_at":"2026-11-08T02:36:49.037074Z"}],"euvd":[{"id":"EUVD-2026-119366","description":"Hickory DNS hickory-proto 0.25.0-alpha.3 through 0.25.2 and hickory-net before 0.26.1 contain an unbounded loop vulnerability in DnssecDnsHandle NSEC3 closest-encloser proof validation when the SOA owner is not an ancestor of the QNAME. Upstream attackers can return NoData or NXDomain responses with a cross-zone SOA record to panic debug builds or exhaust memory in release builds.","status":"published","published":"2026-11-08T01:38:33Z","modified":"2026-11-08T01:38:33Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-08T06:12:04.155226Z"}],"ghsa":[{"id":"GHSA-3v94-mw7p-v465","title":"hickory-proto: NSEC3 closest-encloser proof validation enters unbounded loop on cross-zone responses","description":"The NSEC3 closest-encloser proof validation in `hickory-proto`'s (0.25.0-alpha.3 ... 0.25.2) and `hickory-net`'s (0.26.0-alpha.1 .. 0.26.0)  `DnssecDnsHandle` walks from the QNAME up to the SOA owner name, building a list of candidate encloser names. The iterator used assumes the QNAME is a descendant of the SOA owner, terminating only when the current candidate equals the SOA name. When the SOA in a response's authority section is not an ancestor of the QNAME, the loop stalls at the DNS root and never terminates, repeatedly calling `Name::base_name()` and pushing newly allocated `Name` and hashed-name entries into the candidate `Vec`.\n\nThe bug is reachable by any caller of `DnssecDnsHandle`, including the resolver, recursor, and client, when built with the `dnssec-ring` or `dnssec-aws-lc-rs` feature and configured to perform DNSSEC validation. It is triggered while validating a NoData or NXDomain response whose authority section contains an SOA record from a zone other than an ancestor of the QNAME, on a code path that requires NSEC3 closest-encloser proof. In practice this can be reached through an insecure CNAME chain that crosses zone boundaries into a DNSSEC-signed zone returning NoData, but the minimum condition is just a mismatched SOA owner on a response requiring NSEC3 validation.\n\nA `debug_assert_ne!(name, Name::root())` guards the loop body, so debug builds abort with a panic on the first iteration past the root. Release builds compile the assertion out and run the loop unbounded, allocating until the process exhausts available memory. A reachable upstream attacker who can return such a response can therefore crash a debug build or exhaust memory on a release build, for the affected configurations.\n\nThe affected code was migrated from `hickory-proto` to `hickory-net` as part of the 0.26.0 release. Hickory DNS recommends that all affected users update to `hickory-net` 0.26.1 for the fix.\n\n### Reporter\n\nDavid Cook, ISRG","status":"published","published":"2026-05-07T02:59:20Z","modified":"2026-05-07T02:59:21Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-835"],"updated_at":"2026-11-02T14:40:03.762927Z"},{"id":"GHSA-jvpj-j4xv-2492","title":"Hickory DNS hickory-proto 0.25.0-alpha.3 through 0.25.2 and hickory-net before 0.26.1 contain an...","description":"Hickory DNS hickory-proto 0.25.0-alpha.3 through 0.25.2 and hickory-net before 0.26.1 contain an unbounded loop vulnerability in DnssecDnsHandle NSEC3 closest-encloser proof validation when the SOA owner is not an ancestor of the QNAME. Upstream attackers can return NoData or NXDomain responses with a cross-zone SOA record to panic debug builds or exhaust memory in release builds.","status":"published","published":"2026-11-08T03:30:37Z","modified":"2026-11-08T03:30:44Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-835"],"updated_at":"2026-11-08T03:41:54.072675Z"}],"nvd":[{"id":"CVE-2026-123607","description":"Hickory DNS hickory-proto 0.25.0-alpha.3 through 0.25.2 and hickory-net before 0.26.1 contain an unbounded loop vulnerability in DnssecDnsHandle NSEC3 closest-encloser proof validation when the SOA owner is not an ancestor of the QNAME. Upstream attackers can return NoData or NXDomain responses with a cross-zone SOA record to panic debug builds or exhaust memory in release builds.","status":"published","published":"2026-11-08T02:16:55.747Z","modified":"2026-11-10T22:15:59.797Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"}],"cwes":["CWE-835"],"updated_at":"2026-11-08T07:09:05.855788Z"}],"osv":[{"id":"CVE-2026-123607","title":"Hickory DNS NSEC3 Closest-Encloser Proof Unbounded Loop Denial of Service","description":"Hickory DNS hickory-proto 0.25.0-alpha.3 through 0.25.2 and hickory-net before 0.26.1 contain an unbounded loop vulnerability in DnssecDnsHandle NSEC3 closest-encloser proof validation when the SOA owner is not an ancestor of the QNAME. Upstream attackers can return NoData or NXDomain responses with a cross-zone SOA record to panic debug builds or exhaust memory in release builds.","status":"published","published":"2026-11-08T01:38:33.416Z","modified":"2026-11-09T02:30:53.702458063Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-835"],"updated_at":"2026-11-08T11:04:05.022583Z"},{"id":"GHSA-3v94-mw7p-v465","title":"hickory-proto: NSEC3 closest-encloser proof validation enters unbounded loop on cross-zone responses","description":"The NSEC3 closest-encloser proof validation in `hickory-proto`'s (0.25.0-alpha.3 ... 0.25.2) and `hickory-net`'s (0.26.0-alpha.1 .. 0.26.0)  `DnssecDnsHandle` walks from the QNAME up to the SOA owner name, building a list of candidate encloser names. The iterator used assumes the QNAME is a descendant of the SOA owner, terminating only when the current candidate equals the SOA name. When the SOA in a response's authority section is not an ancestor of the QNAME, the loop stalls at the DNS root and never terminates, repeatedly calling `Name::base_name()` and pushing newly allocated `Name` and hashed-name entries into the candidate `Vec`.\n\nThe bug is reachable by any caller of `DnssecDnsHandle`, including the resolver, recursor, and client, when built with the `dnssec-ring` or `dnssec-aws-lc-rs` feature and configured to perform DNSSEC validation. It is triggered while validating a NoData or NXDomain response whose authority section contains an SOA record from a zone other than an ancestor of the QNAME, on a code path that requires NSEC3 closest-encloser proof. In practice this can be reached through an insecure CNAME chain that crosses zone boundaries into a DNSSEC-signed zone returning NoData, but the minimum condition is just a mismatched SOA owner on a response requiring NSEC3 validation.\n\nA `debug_assert_ne!(name, Name::root())` guards the loop body, so debug builds abort with a panic on the first iteration past the root. Release builds compile the assertion out and run the loop unbounded, allocating until the process exhausts available memory. A reachable upstream attacker who can return such a response can therefore crash a debug build or exhaust memory on a release build, for the affected configurations.\n\nThe affected code was migrated from `hickory-proto` to `hickory-net` as part of the 0.26.0 release. Hickory DNS recommends that all affected users update to `hickory-net` 0.26.1 for the fix.\n\n### Reporter\n\nDavid Cook, ISRG","status":"published","published":"2026-05-07T02:59:20Z","modified":"2026-11-08T10:55:55.393700581Z","cvss":[{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-835"],"updated_at":"2026-11-08T11:04:05.022583Z"},{"id":"UBUNTU-CVE-2026-123607","description":"Hickory DNS hickory-proto 0.25.0-alpha.3 through 0.25.2 and hickory-net before 0.26.1 contain an unbounded loop vulnerability in DnssecDnsHandle NSEC3 closest-encloser proof validation when the SOA owner is not an ancestor of the QNAME. Upstream attackers can return NoData or NXDomain responses with a cross-zone SOA record to panic debug builds or exhaust memory in release builds.","status":"published","published":"2026-11-09T00:00:00Z","modified":"2026-11-10T02:49:53.613434638Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"},{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-10T03:18:58.105788Z"},{"id":"RUSTSEC-2026-0118","title":"NSEC3 closest-encloser proof validation enters unbounded loop on cross-zone responses","description":"The NSEC3 closest-encloser proof validation in `hickory-proto`'s\n`DnssecDnsHandle` walks from the QNAME up to the SOA owner name, building a\nlist of candidate encloser names. The iterator used assumes the\nQNAME is a descendant of the SOA owner, terminating only when the current\ncandidate equals the SOA name. When the SOA in a response's authority section\nis not an ancestor of the QNAME, the loop stalls at the DNS root and never\nterminates, repeatedly calling `Name::base_name()` and pushing newly allocated\n`Name` and hashed-name entries into the candidate `Vec`.\n\nThe bug is reachable by any caller of `DnssecDnsHandle` — including the\nresolver, recursor, and client — when built with the `dnssec-ring` or\n`dnssec-aws-lc-rs` feature and configured to perform DNSSEC validation. It is\ntriggered while validating a NoData or NXDomain response whose authority\nsection contains an SOA record from a zone other than an ancestor of the\nQNAME, on a code path that requires NSEC3 closest-encloser proof. In practice\nthis can be reached through an insecure CNAME chain that crosses zone\nboundaries into a DNSSEC-signed zone returning NoData, but the minimum\ncondition is just a mismatched SOA owner on a response requiring NSEC3\nvalidation.\n\nA `debug_assert_ne!(name, Name::root())` guards the loop body, so debug builds\nabort with a panic on the first iteration past the root. Release builds\ncompile the assertion out and run the loop unbounded, allocating until the\nprocess exhausts available memory (OOM). A reachable upstream attacker who\ncan return such a response can therefore crash a debug-built validator or\nexhaust memory on a release-built one.\n\nThe affected code was migrated from `hickory-proto` to `hickory-net` as part of\nthe 0.26.0 release. The `hickory-proto` 0.26.x release no longer offers\n`DnssecDnsHandle` and so we recommend all affected users update to `hickory-net`\n0.26.1 when the implementation of that type is required.","status":"published","published":"2026-05-01T12:00:00Z","modified":"2026-11-09T09:21:20Z","updated_at":"2026-11-08T11:04:05.022583Z"},{"id":"RUSTSEC-2026-0120","title":"NSEC3 closest-encloser proof validation enters unbounded loop on cross-zone responses","description":"The NSEC3 closest-encloser proof validation in `hickory-net`'s\n`DnssecDnsHandle` walks from the QNAME up to the SOA owner name, building a\nlist of candidate encloser names. The iterator used assumes the\nQNAME is a descendant of the SOA owner, terminating only when the current\ncandidate equals the SOA name. When the SOA in a response's authority section\nis not an ancestor of the QNAME, the loop stalls at the DNS root and never\nterminates, repeatedly calling `Name::base_name()` and pushing newly allocated\n`Name` and hashed-name entries into the candidate `Vec`.\n\nThe bug is reachable by any caller of `DnssecDnsHandle` — including the\nresolver, recursor, and client — when built with the `dnssec-ring` or\n`dnssec-aws-lc-rs` feature and configured to perform DNSSEC validation. It is\ntriggered while validating a NoData or NXDomain response whose authority\nsection contains an SOA record from a zone other than an ancestor of the\nQNAME, on a code path that requires NSEC3 closest-encloser proof. In practice\nthis can be reached through an insecure CNAME chain that crosses zone\nboundaries into a DNSSEC-signed zone returning NoData, but the minimum\ncondition is just a mismatched SOA owner on a response requiring NSEC3\nvalidation.\n\nA `debug_assert_ne!(name, Name::root())` guards the loop body, so debug builds\nabort with a panic on the first iteration past the root. Release builds\ncompile the assertion out and run the loop unbounded, allocating until the\nprocess exhausts available memory (OOM). A reachable upstream attacker who\ncan return such a response can therefore crash a debug-built validator or\nexhaust memory on a release-built one.\n\nWe recommend all affected users update to `hickory-net` 0.26.1 for the fix.","status":"published","published":"2026-05-01T12:00:00Z","modified":"2026-11-09T09:21:20Z","updated_at":"2026-11-08T11:04:05.022583Z"}]}}