CVE-2026-123596

NameCVE-2026-123596
DescriptionHickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain a DNSSEC validation flaw in the validating recursor's NSEC handler that accepts parent-side ancestor-delegation NSEC records as proof of nonexistence for names below the zone cut. An on-path attacker, rogue parent nameserver, or attacker winning a port and TXID race can deliver one forged NXDOMAIN response built from genuinely signed parent NSEC records, causing authenticated denial of existing child-zone names cached for the negative TTL.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
rust-hickory-net (PTS)forky, sid0.26.3-1fixed
rust-hickory-proto (PTS)trixie0.24.4-2vulnerable
forky, sid0.26.3-1vulnerable

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
rust-hickory-netsource(unstable)0.26.3-1
rust-hickory-protosource(unstable)(unfixed)

Notes

https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-3r6v-f3jh-vvqm

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