WS-2026-0133
Published:October 20, 2026
Updated:October 22, 2026
certifi 2019.03.09 through 2026.07.22 ships the "emSign ECC Root CA - G3" root certificate in its CA bundle (certifi/cacert.pem). Intermediates under this root were revoked for key compromise (cACompromise), so certificates issued with the compromised CA keys are trusted by applications that use certifi, enabling man-in-the-middle attacks. Fixed in 2026.10.18, which removed the root; 2026.10.19 restored the unaffected emSign roots and keeps G3 removed.
Affected Packages
certifi (CONDA):
Affected version(s) >=2019.3.9 <2026.10.19Fix Suggestion:
Update to version 2026.10.19https://github.com/certifi/python-certifi.git (GITHUB):
Affected version(s) >=2019.03.09 <2026.10.19Fix Suggestion:
Update to version 2026.10.19certifi (PYTHON):
Affected version(s) >=2019.3.9 <2026.10.19Fix Suggestion:
Update to version 2026.10.19Related Resources (4)
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Contact UsCVSS v4
Base Score:
9.1
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.4
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
Insufficient Verification of Data Authenticity