certifi bundles emSign root CAs with compromised intermediate CA keys (Critical severity, GHSA-6q48-6c7w-9gw2)
A critical-severity advisory for the pip package certifi is fixed in version 2026.10.19.
Key points
- certifi (pip) has a critical flaw.
- Tracked as GHSA-6q48-6c7w-9gw2.
- Version 2026.10.19.
Maintainers of certifi, a package in the pip ecosystem, have published a critical-severity security advisory (GHSA-6q48-6c7w-9gw2): certifi bundles emSign root CAs with compromised intermediate CA keys.
At a glance
- Advisory
- GHSA-6q48-6c7w-9gw2
- CVE
- Not assigned
- Package
- certifi (pip)
- Severity
- Critical
- Patched in
- 2026.10.19
What is the issue?
The GitHub-reviewed advisory explains: Certifi versions before 2026.10.18 include the emSign ECC Root CA - G3 root certificate in their bundled CA store. Eight eMudhra intermediate CA certificates that chain to this root have compromised private keys and the CA has revoked them. An attacker with one of the compromised keys can issue valid-looking certificates for any hostname. If the attacker is also on-path, they can intercept or modify TLS traffic from clients that trust the certifi bundle. Examples include requests, urllib3 and pip, and the Python.org macOS installer. Certifi 2026.10.18 removed all emSign roots from the bundle. Certifi 2026.10.19 restored the emSign roots that are not affected. Upgrade to 2026.10.19 or later, and rebuild container images that vendor certifi.
Affected versions
| Ecosystem | Package | Vulnerable | Patched |
|---|---|---|---|
| pip | certifi | >= 2019.03.09, < 2026.10.19 | 2026.10.19 |
How to fix it
- Upgrade the affected package to the first patched version listed above.
- Rebuild and redeploy applications that bundle the vulnerable dependency.
- Run your dependency scanner (npm audit, pip-audit, Dependabot) to find transitive uses.
- Review the advisory references for workaround details if you cannot upgrade yet.
What to do and how to stay safe: GHSA-6q48-6c7w-9gw2
- Vulnerability severity scores ignore your specific architecture and context.
- Exploitability depends on network exposure and user behavior, not just code flaws.
- Prioritization requires continuous asset inventory and threat intelligence alignment.
Risk-based vulnerability management focuses your limited resources on the flaws that actually threaten your business. Start by mapping your critical assets and checking for active exploits to prioritize your backlog.
Step-by-step guide: Risk-Based Vulnerability Management: Prioritize Fixes by Actual Danger
General security guidance from the Threat Times newsroom. It is not confirmed advice from the organisations named in this story.
