CPython flaws enable remote DoS and data compromise
Multiple vulnerabilities in CPython allow remote denial of service, data confidentiality breaches, and integrity violations; patches available from the vendor.
Sourcecert.ssi.gouv.fr — open the original
What to check
- Applies to
- The 3 CVEs 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.
The French CERT (CERT-FR) has issued an advisory regarding multiple security vulnerabilities discovered in CPython, the reference implementation of the Python programming language. The flaws affect systems running CPython without the latest security patches and pose risks to data integrity, confidentiality, and availability.
The vulnerabilities enable attackers to execute remote denial-of-service attacks, compromise the confidentiality of data, and violate data integrity. Three CVEs have been assigned to track these issues: CVE-2026-0864, CVE-2026-11940, and CVE-2026-11972. Python's security team released patches on June 23, 2026, addressing all identified vulnerabilities.
Organizations running CPython-based applications should prioritize applying the available security updates. Given Python's widespread use across enterprise applications, web services, and automation frameworks, the potential attack surface is significant. Administrators should consult the vendor bulletins for specific patch guidance and version compatibility information.
Mentioned in this report
Source reporting: https://www.cert.ssi.gouv.fr/avis/CERTFR-2026-AVI-0800
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