Improper input validation in Python
CVE-2026-3644
The fix for CVE-2026-0672, which rejected control characters in http.cookies.Morsel, was incomplete. The Morsel.update(), |= operator, and unpickling paths were not patched, allowing control characters to bypass input validation. Additiona…
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
EPSS: 0.001 (19.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
Affected products
- Python — versions 3.15.0
- Python Software Foundation Cpython — versions 0, 3.14.0, 3.15.0a1
Weakness classification (CWE)
References
- cna@python.org (vendor-advisory, Third Party Advisory)
- cna@python.org (Patch, patch)
- cna@python.org (issue-tracking, Issue Tracking)
- cna@python.org (Patch, patch)
- cna@python.org (Patch, patch)
- cna@python.org (Patch, patch)
Frequently asked questions
- What is CVE-2026-3644?
- CVE-2026-3644 is a high-severity vulnerability in Python, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2026-03-16.
- How severe is CVE-2026-3644?
- High severity. CVSS v3 base score is 7.5 out of 10.