Is This vulnerability exploited in the wild?

No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

How severe is This vulnerability?

Medium severity, with a CVSS score of 4, published 20 October 2026.

Which products and versions are affected?

certifi (PyPI) ECOSYSTEM:introduced=2019.03.09,fixed=2026.10.19; Python Software Foundation Certifi 2019.03.09 through 2026.10.18.

Is there a fix for This vulnerability?

Yes. certifi (PyPI): upgrade to 2026.10.19 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is This vulnerability attacked?

It is attacked over the network or from the adjacent network, in a software library.

Check whether you run certifi (PyPI) or Python Software Foundation Certifi at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

certifi bundled root CA compromised intermediate key exposure

Severity: medium · CVSS 4 · Published 2026-10-20

certifi is a Python library that provides trusted root certificates used by web libraries like requests and pip to verify secure connections. Eight intermediate certificates issued by emSign root CA have had their private keys compromised, allowing an attacker to issue fake certificates for any website. An attacker positioned between a user and a server could intercept or modify encrypted traffic from applications that use certifi.

Technologies: certifi (PyPI). Vendors: PyPI, Python Software Foundation.

Quick answers

Is This vulnerability exploited in the wild?: No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.
How severe is This vulnerability?: Medium severity, with a CVSS score of 4, published 20 October 2026.
Which products and versions are affected?: certifi (PyPI) ECOSYSTEM:introduced=2019.03.09,fixed=2026.10.19; Python Software Foundation Certifi 2019.03.09 through 2026.10.18.
Is there a fix for This vulnerability?: Yes. certifi (PyPI): upgrade to 2026.10.19 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is This vulnerability attacked?: It is attacked over the network or from the adjacent network, in a software library.
Am I affected?: Check whether you run certifi (PyPI) or Python Software Foundation Certifi at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

certifi (PyPI): upgrade to 2026.10.19 or later
```
pip install "certifi>=2026.10.19"
```

Technical details

The vulnerability exists in certifi versions 2019.03.09 through 2026.10.18, which bundle the emSign ECC Root CA - G3 root certificate. Eight eMudhra intermediate CA certificates chained to this root have revoked private keys; an attacker with one of these keys can forge valid-looking certificates for any hostname. The attack requires network positioning (on-path) between the client and server, and affects applications like requests, urllib3, pip, and Python's macOS installer that rely on certifi's bundled CA store.

Affected products

Python Software Foundation certifi 2019.03.09 through 2026.10.18

Identifiers

GHSA-6q48-6c7w-9gw2
PYSEC-2026-4320

Timeline

2026-10-20: disclosed
2026-10-19: patched

References

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