GitHub Advisoryadvisory · PyPI

GHSA-hq85-5cpj-mr62 uv's bundled CA store trusts an emSign root whose intermediate CA keys are compromised

CRITICAL Published 2026-10-20 Modified 2026-10-20 Official page ↗
Ecosystem
PyPI
Packages
uv
Severity
Critical
CVSS vector
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Weaknesses
CWE-295
Reviewed
2026-10-20

Affected packages

• PyPI uv: < 0.13.4 → fixed in 0.13.4

Description

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.

Related

Weakness · CWE (1)

  • CWE-295 Improper Certificate Validation weakness

References