How severe is GHSA-hq85-5cpj-mr62?

No CVSS score has been assigned to GHSA-hq85-5cpj-mr62 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-hq85-5cpj-mr62?

GHSA-hq85-5cpj-mr62 affects the following packages: uv (PyPI). Ecosystems affected: PyPI.

How do I fix GHSA-hq85-5cpj-mr62?

Update uv to 0.13.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hq85-5cpj-mr62 is resolved across your whole dependency graph.

How do I detect GHSA-hq85-5cpj-mr62 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for uv, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-hq85-5cpj-mr62 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is GHSA-hq85-5cpj-mr62 actively exploited in the wild?

No public exploit code has been indexed for GHSA-hq85-5cpj-mr62 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was GHSA-hq85-5cpj-mr62 published, and has it been updated?

GHSA-hq85-5cpj-mr62 was published on October 20, 2026 and was last updated on October 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

Not in CISA KEV

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

GHSA-hq85-5cpj-mr62 is a security vulnerability in uv. A fix is available for uv — see the affected versions and patch details below.

Also known asPYSEC-2026-4321

Published

Oct 20, 2026

Updated

Oct 20, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 20, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

🐍uv

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

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.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`uv`	all versions	0.13.4`pip install --upgrade 'uv==0.13.4'`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for uv, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update uv to 0.13.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hq85-5cpj-mr62 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

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.

O3 Security · Impact-Aware SCA

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