Vulnerability in CPython (July 30, 2026)

unknownCVE-2026-6879

A vulnerability has been discovered in CPython. It allows an attacker to cause a remote denial of service.

CSIRTS triage

vendor: Python Software Foundation product: CPython Denial of service

What: A vulnerability allows an attacker to cause a remote denial of service.
Who is affected: Users of CPython are affected.
Urgency: Remediation is necessary, but the vulnerability is not actively exploited.
Action: Users should apply updates as they become available.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: CERT-FR Avis de sécurité (FR · national-cert · site)
Severity: unknown
Published: 2026-07-30
Exploitation: Not in CISA KEV at last sync
Language: Machine-translated to English — verify against the original

Original advisory: https://www.cert.ssi.gouv.fr/avis/CERTFR-2026-AVI-0944/

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-68790.29% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 22% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-6879	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

unknownCVE-2026-6879: `Element.findall()` and fully-consumed `Element.iterfind()` exhibit `O(n^2)` time complexity wh…nvd

Recent advisories for CPython

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

high[NEW] [high] CPython: Vulnerability allows Denial of Servicecert-bund · 2026-07-31
medium[UPDATE] [medium] CPython: Multiple vulnerabilitiescert-bund · 2026-07-31
medium[UPDATE] [medium] CPython: Multiple vulnerabilitiescert-bund · 2026-07-31
low[UPDATE] [low] CPython: Vulnerability allows Denial of Servicecert-bund · 2026-07-31
high[UPDATE] [high] CPython: Multiple vulnerabilitiescert-bund · 2026-07-28
medium[UPDATE] [medium] CPython: Vulnerability allows data manipulationcert-bund · 2026-07-28