CVE-2026-96405

NameCVE-2026-96405
DescriptionNLnet Labs Unbound up to and including version 1.26.1 limits compression-pointer traversal for each individual domain-name operation but has no aggregate inbound decompression-work budget. Many chained compression pointers in a message results in a lot of CPU usage following them. A malicious actor with recursive-query access and control of an ordinarily delegated authority that serves specially crafted replies can exploit the vulnerability and degrade Unbound's general performance.
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)
ReferencesDSA-6581-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
unbound (PTS)bookworm1.17.1-2+deb12u4vulnerable
bookworm (security)1.17.1-2+deb12u3vulnerable
trixie1.22.0-2+deb13u3vulnerable
trixie (security)1.26.2-0+deb13u1fixed
forky, sid1.26.2-1fixed

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

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
unboundsourcetrixie1.26.2-0+deb13u1DSA-6581-1
unboundsource(unstable)1.26.2-1

Notes

https://community.nlnetlabs.nl/t/unbound-1-26-2-released/3495

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