CPython CVE-2026-9669 enables remote DoS
A vulnerability in CPython allows attackers to trigger remote denial of service against unpatched systems.
Sourcecert.ssi.gouv.fr — open the original
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.
The French national cybersecurity agency ANSSI has published an advisory warning of a denial-of-service vulnerability in CPython, tracked as CVE-2026-9669. The flaw affects CPython installations that have not applied the latest security patch.
The vulnerability permits remote attackers to cause a denial-of-service condition without requiring authentication or user interaction. The Python Software Foundation released security patches on June 8, 2026, addressing this issue across supported versions.
Organisations running Python-based applications and services should prioritise patching to mitigate the risk of service disruption. The advisory recommends consulting the official Python security bulletin for patch availability and deployment guidance.
Mentioned in this report
Source reporting: https://www.cert.ssi.gouv.fr/avis/CERTFR-2026-AVI-0704
Free public brief. Slack alerts on the vendors you run come with the paid plans, and a new account gets three days of them, no card.
What this brief leaves out
This page is the free tier: the write-up, the severity, the names. 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.
It sits in a corpus of 16,436 reports from 149 sources, 661 of them written in the last seven days, and it grows through the day.
A new account starts with three days of all of it, no card, then keeps the government and CERT reporting free. Slack alerts are a paid-plan feature: name the vendors you run and Slack hears about the reports that touch them, not the rest of the week's. Nothing is charged unless you subscribe.
Create a free account What it costs