CVE-2026-83813
Twisted: DNS Response Spoofing in twisted.names Due to Missing Source Address Validation
Impact
Twisted 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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | Twisted | <= 26.4.0 | 26.10.0rc1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-jj36-9pvh-vj5r
- https://github.com/twisted/twisted/security/advisories/GHSA-jj36-9pvh-vj5r
- https://nvd.nist.gov/vuln/detail/CVE-2026-83813
- https://github.com/twisted/twisted/pull/12700
- https://github.com/twisted/twisted/commit/b53e1c3477c209b5609a1c74cf9e48373b5879ac
- https://github.com/twisted/twisted/releases/tag/twisted-26.10.0rc1