CVE-2026-114605: dnspython dns.name.from_wire_parser() excessive CPU use

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-22 · updated 2026-10-29
Weakness: CWE-674

Description

dnspython is a DNS toolkit for Python. Prior to 2.9.0, dns.name.from_wire_parser follows attacker-controlled DNS compression pointer chains without a hop limit. A malicious DNS wire-format message can force excessive pointer traversal during name decompression, causing high CPU use, application degradation, or denial of service in applications that process untrusted DNS messages. This issue is fixed in version 2.9.0.

Affected products

rthalley dnspython: before 2.9.0

References

https://github.com/rthalley/dnspython/commit/b485e460c266540a1a09ca6d8d1d7b685b1d3023
https://github.com/rthalley/dnspython/releases/tag/v2.9.0
https://github.com/rthalley/dnspython/security/advisories/GHSA-45c3-73f7-pv4m

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