hickory-proto: NSEC3 closest-encloser proof validation enters unbounded loop on cross-zone responses

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.7 · 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 · score source

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

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::basename() 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…

Published by the source

7 May 2026, 02:59 UTC

Last modified by the source

7 May 2026, 02:59 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-3v94-mw7p-v465

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# Patch Next advisory brief: GHSA-3v94-mw7p-v465

Advisory: hickory-proto: NSEC3 closest-encloser proof validation enters unbounded loop on cross-zone responses
IDs: GHSA-3v94-mw7p-v465
Record: https://patchnext.com/advisories/ghsa-3v94-mw7p-v465 (revision 1, source checked 26 Oct 2026, 15:42 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Partial vendor fix; fixed versions by package: hickory-net 0.26.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io hickory-net: affected >= 0.26.0-alpha.1, <= 0.26.0; fixed in 0.26.1
- crates.io hickory-proto: affected >= 0.25.0-alpha.3, <= 0.25.2

## Suggested inspection (read-only)
- crates.io hickory-net: check the installed version with your package manager.
- crates.io hickory-proto: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on hickory-net, hickory-proto.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-3v94-mw7p-v465 (GitHub-reviewed advisory GHSA-3v94-mw7p-v465 lists affected ranges: crates.io hickory-proto >=0.25.0-alpha.3 =0.26.0-alpha.1 <=0.26.0)

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