A AegiFlow
CRITICALCVSS 9.1

GHSA-hq85-5cpj-mr62

uv's bundled CA store trusts an emSign root whose intermediate CA keys are compromised

Published
2026-10-20
Modified
2026-10-20
Sources
github-advisory

Summary

By default, uv verifies TLS connections against a vendored copy of the `webpki-root-certs` bundle. Versions before 0.13.4 include the `emSign ECC Root CA - G3` root. Eight eMudhra intermediate CA certificates that chain to that root have compromised private keys, and the CA has revoked them. An attacker with one of the compromised keys can issue certificates that uv accepts for any hostname, and can be used to issue certificates to enable MITM attacks. uv 0.13.4 removes the root from its vendored bundle, following `webpki-root-certs` 1.0.10. Upgrade to 0.13.4 or later.

Affected packages

EcosystemPackageAffected versionsFixed versions
PyPIuv—0.13.4

Remediation: Upgrade to 0.13.4 or later.

References

Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.