CVE-2026-128089

NameCVE-2026-128089
Descriptiondnspython is a DNS toolkit for Python. Prior to version 2.9.2, the from_text() parser for WKS records does not require the service number to be between 0 and 65535 before using it as a bitmap offset. An attacker-controlled zone file can supply a larger number, causing the service bitmap to grow to an extremely large size through inefficient repeated extension, consuming excessive memory and CPU and potentially terminating the process. Applications are affected only when they parse zone-file text whose record type and rdata are attacker controlled. This issue is fixed in version 2.9.2.
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)
Debian Bugs1153955

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
dnspython (PTS)bookworm2.3.0-1vulnerable
bookworm (security)2.3.0-1+deb12u1vulnerable
trixie2.7.0-1vulnerable
forky, sid2.8.0-7vulnerable

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

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
dnspythonsource(unstable)(unfixed)1153955

Notes

https://github.com/rthalley/dnspython/security/advisories/GHSA-vvf4-9x63-8xvv
Fixed by: https://github.com/rthalley/dnspython/commit/388db14ee9923288f6e73f86e482c77706e59d73 (v2.9.2)

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