RUSTSEC-2026-0120 (GHSA-3V94-MW7P-V465)
Vulnerability from osv_rustsec – Published: 2026-05-01 12:00 – Updated: 2026-05-07 08:56 – Source websiteThe NSEC3 closest-encloser proof validation in hickory-net's
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.
The 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.
A 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 (OOM). A reachable upstream attacker who
can return such a response can therefore crash a debug-built validator or
exhaust memory on a release-built one.
We recommend all affected users update to hickory-net 0.26.1 for the fix.
| URL | Type | |
|---|---|---|
{
"affected": [
{
"database_specific": {
"categories": [
"denial-of-service"
],
"cvss": null,
"informational": null
},
"ecosystem_specific": {
"affected_functions": null,
"affects": {
"arch": [],
"functions": [],
"os": []
}
},
"package": {
"ecosystem": "crates.io",
"name": "hickory-net",
"purl": "pkg:cargo/hickory-net"
},
"ranges": [
{
"events": [
{
"introduced": "0.0.0-0"
},
{
"fixed": "0.26.1"
}
],
"type": "SEMVER"
}
],
"versions": []
}
],
"aliases": [
"GHSA-3v94-mw7p-v465"
],
"database_specific": {
"license": "CC-BY-4.0"
},
"details": "The NSEC3 closest-encloser proof validation in `hickory-net`\u0027s\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\u0027s 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` \u2014 including the\nresolver, recursor, and client \u2014 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.",
"id": "RUSTSEC-2026-0120",
"modified": "2026-05-07T08:56:41Z",
"published": "2026-05-01T12:00:00Z",
"references": [
{
"type": "PACKAGE",
"url": "https://crates.io/crates/hickory-net"
},
{
"type": "ADVISORY",
"url": "https://rustsec.org/advisories/RUSTSEC-2026-0120.html"
},
{
"type": "ADVISORY",
"url": "https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-3v94-mw7p-v465"
}
],
"related": [],
"severity": [],
"summary": "NSEC3 closest-encloser proof validation enters unbounded loop on cross-zone responses"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
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