CVE-2026-123594

Name	CVE-2026-123594
Description	Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain an NSEC validation flaw that returns a secure proof for NXDOMAIN responses when the covering NSEC's Next Domain Name is a strict descendant of the query name, which actually proves the name exists as an empty non-terminal. On-path attackers can flip the unsigned rcode of a genuine signed NODATA response from NOERROR to NXDOMAIN, causing validators to accept forged nonexistence of the name.
Source	CVE (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 Package	Release	Version	Status
rust-hickory-net (PTS)	forky, sid	0.26.3-1	fixed
rust-hickory-proto (PTS)	trixie	0.24.4-2	vulnerable
	forky, sid	0.26.3-1	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
rust-hickory-net	source	(unstable)	0.26.3-1
rust-hickory-proto	source	(unstable)	(unfixed)

https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-86vr-jm6c-7cpg