CVE-2026-83813

NameCVE-2026-83813
DescriptionTwisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.10.0rc1, twisted.names.dns.DNSDatagramProtocol accepts a UDP DNS response for a pending query when its 16-bit transaction ID matches but does not verify that the response came from the queried host and port. An attacker able to deliver a packet to the resolver's listening port with the correct transaction ID can inject a forged answer. The standard twisted.names.client.Resolver uses a new random source port for each query, increasing off-path attack complexity, while applications that reuse a DNSDatagramProtocol instance expose only the transaction-ID search space after the first query. A successful forgery can redirect hostname resolution and enable mail interception, server-side request forgery, or man-in-the-middle positioning. This issue is fixed in version 26.10.0rc1.
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 Bugs1151938

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
twisted (PTS)bookworm, bookworm (security)22.4.0-4+deb12u1vulnerable
trixie24.11.0-1vulnerable
sid, forky26.4.0-6vulnerable

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

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
twistedsource(unstable)(unfixed)1151938

Notes

[trixie] - twisted <no-dsa> (Minor issue)
https://github.com/twisted/twisted/security/advisories/GHSA-jj36-9pvh-vj5r
https://github.com/twisted/twisted/pull/12700
Fixed by: https://github.com/twisted/twisted/commit/b53e1c3477c209b5609a1c74cf9e48373b5879ac (twisted-26.10.0rc1)

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