GHSA-5qpg-rh4j-qp35: pycares has a Use-After-Free Vulnerability

June 16, 2025

pycares is vulnerable to a use-after-free condition that occurs when a Channel object is garbage collected while DNS queries are still pending. This results in a fatal Python error and interpreter crash.

References

github.com/advisories/GHSA-5qpg-rh4j-qp35
github.com/saghul/pycares
github.com/saghul/pycares/commit/ebfd7d71eb8e74bc1057a361ea79a5906db510d4
github.com/saghul/pycares/security/advisories/GHSA-5qpg-rh4j-qp35

Code Behaviors & Features

Detect and mitigate GHSA-5qpg-rh4j-qp35 with GitLab Dependency Scanning

Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Dependency Scanning using SBOM also detects vulnerabilities from proprietary advisories that this site does not include. Learn more about Dependency Scanning using SBOM →