Resource exhaustion in Python
CVE-2025-13836
When reading an HTTP response from a server, if no read amount is specified, the default behavior will be to use Content-Length. This allows a malicious server to cause the client to read large amounts of data into memory, potentially causing OOM or other DoS.
Vulnerability class: DoS (Denial of Service)
EPSS: 0.015 (72.1th 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:N/A:H.
Affected products
- Python — versions 3.14.0, 3.15.0
- Python Software Foundation Cpython — versions 0, 3.11.0, 3.12.0
Weakness classification (CWE)
References
- cna@python.org (issue-tracking, Patch, Issue Tracking)
- cna@python.org (Patch, patch, Issue Tracking)
- cna@python.org (Patch, patch)
- cna@python.org (Patch, patch)
- cna@python.org (vendor-advisory, Vendor Advisory)
- cna@python.org (Patch, patch)
- cna@python.org (Patch, patch)
- cna@python.org (Patch, patch)
- cna@python.org (Patch, patch)
Frequently asked questions
- What is CVE-2025-13836?
- CVE-2025-13836 is a high-severity vulnerability in Python, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2025-12-01.
- How severe is CVE-2025-13836?
- High severity. CVSS v3 base score is 7.5 out of 10.