CVE-2026-83813 Twisted: DNS Response Spoofing in twisted.names Due to Missing Source Address Validation
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-83813?
CVE-2026-83813 is a low-severity vulnerability in twisted, published on 23 Oct 2026.
Official description
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.
Weakness: CWE-346
Which versions are affected by CVE-2026-83813?
2 open source packages ship an affected version, including Twisted and twisted.
| Package | Affected | Fixed in |
|---|---|---|
Twisted PyPI | All versions | 26.10.0rc1 |
twisted PyPI | All versions | 26.10.0rc1 |
How do I fix CVE-2026-83813?
Upgrade Twisted to 26.10.0rc1 or later.
Is CVE-2026-83813 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-83813 exists.
Sources
Also known as AZL-111419, DEBIAN-CVE-2026-83813, ECHO-487e-7daf-726c, GHSA-jj36-9pvh-vj5r, UBUNTU-CVE-2026-83813.