# CERT-FR Flags CPython Security Bypass Flaw

Published: 2026-10-28 · Severity: elevated · Sectors: Technology
Canonical: https://vorant.io/reports/2911b5be-85eb-51fb-95c7-dbcc4a6a7fdd/cert-fr-flags-cpython-security-bypass-flaw
Vorant's rating weighs the evidence in the report: confirmed exploitation, victims claimed, CVSS and EPSS, and how many sources agree. It rates the report, not your assets.

> CERT-FR advises patching CPython to fix a flaw allowing attackers to bypass security policy, tracked as CVE-2026-103995.

Source: cert.cyber.gouv.fr — https://www.cert.cyber.gouv.fr/avis/CERTFR-2026-AVI-1397

## What to check

- Applies to: The 1 CVE named below. Whether you run an affected version is not assessed: check the versions the source lists.
- Exploitation: No exploitation in the wild and no public exploit is recorded for the CVEs named.

CERT-FR has published an advisory regarding a vulnerability in CPython, the reference implementation of the Python programming language. The flaw, identified as CVE-2026-103995 and documented in Python Software Foundation advisory PSF-2026-47, allows an attacker to bypass security policy controls. The advisory does not specify technical details of the exploitation mechanism, affected version ranges, or whether the vulnerability is being actively exploited in the wild.

Affected systems are any CPython installations that have not applied the latest security patch referenced in the PSF advisory. Defenders should consult the official Python Software Foundation advisory and apply the corresponding patch to remediate the issue. Given the lack of detail on exploitation complexity or active exploitation, and the nature of the impact being a security policy bypass rather than remote code execution or privilege escalation, this should be treated as a routine patching action.

## Mentioned in this report

- Vulnerabilities: CVE-2026-103995

Source reporting: https://www.cert.cyber.gouv.fr/avis/CERTFR-2026-AVI-1397

---

This is the free public brief from Vorant Threat Intelligence. When citing, attribute "Vorant" and link https://vorant.io/reports/2911b5be-85eb-51fb-95c7-dbcc4a6a7fdd/cert-fr-flags-cpython-security-bypass-flaw.
In the app the same report carries live profiles of the CVEs it names. The paid plans add the security research and news reporting the free tier leaves out. Slack alerts on the vendors, sectors and countries a reader follows come with the paid plans too. A new account starts with a three-day trial, no card: https://vorant.io/signup