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

0
Critical
Published: 10/20/2026 (10/20/2026, 19:37:52 UTC)
Source: GCVE Database
Product: uv

Description

The uv software versions before 0.13.4 include a bundled CA root certificate 'emSign ECC Root CA - G3' whose intermediate CA keys have been compromised. This allows an attacker with access to these keys to issue fraudulent certificates trusted by uv, enabling potential man-in-the-middle (MITM) attacks. Version 0.13.4 removes this root from the trusted bundle, mitigating the risk.

CVSS v4.0

Attack Vector
Network
Attack Complexity
High
Attack Requirements
Present
Privileges Required
None
User Interaction
None
Vuln. Confidentiality
High
Vuln. Integrity
High
Vuln. Availability
None
Subsq. Confidentiality
None
Subsq. Integrity
None
Subsq. Availability
None
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

Affected software

PyPIghsa
uv
Affected versions
<0.13.4

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AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 10/20/2026, 22:43:40 UTC

Technical Analysis

Uv verifies TLS connections using a vendored 'webpki-root-certs' bundle. Versions prior to 0.13.4 include the 'emSign ECC Root CA - G3' root certificate. Eight intermediate CA certificates under this root, issued by eMudhra, have compromised private keys and have been revoked by the CA. An attacker possessing one of these compromised keys can issue certificates trusted by uv for any hostname, facilitating MITM attacks. Uv 0.13.4 updates the root certificate bundle to remove this compromised root, following the update in 'webpki-root-certs' version 1.0.10.

Potential Impact

An attacker with one of the compromised intermediate CA private keys can create certificates trusted by uv for any hostname. This undermines TLS security by enabling man-in-the-middle attacks, potentially exposing sensitive data or allowing impersonation of legitimate services.

Mitigation Recommendations

Upgrade uv to version 0.13.4 or later, which removes the compromised 'emSign ECC Root CA - G3' root from the bundled CA store. This update aligns with 'webpki-root-certs' version 1.0.10 and mitigates the vulnerability. Since a patch is available, applying this official fix is the recommended remediation.

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Technical Details

Gcve Source
db.gcve.eu
Osv Id
GHSA-hq85-5cpj-mr62
Osv Schema Version
1.4.0
Ecosystems
["PyPI"]
Database Specific Severity
CRITICAL
Cvss Version
4.0

Threat ID: 6ad7ec4a2cdf04f6566ba0b9

Added to database: 10/20/2026, 22:33:46 UTC

Last enriched: 10/20/2026, 22:43:40 UTC

Last updated: 10/20/2026, 22:43:40 UTC

Views: 10

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