7.5highHigh
CVE-2025-13836
Python Python
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.
Exploitation status
- A vendor advisory or patch reference has been published.
What the metrics mean
- It is reachable over a network, without needing local access.
- For an attacker who can reach it, no special conditions are needed to exploit it.
- To exploit it, no account is needed.
- Beyond that, no action by a user is required.
Scoring
- CVSS
- 7.5 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- CVSS v4
- 6.3
- Weakness
- CWE-400
- Assigned by
- cna@python.org
Dates
- Published
- 2025-12-01
- Last modified
- 2026-09-03
- Sources
- NVD
Affected products
- Python Python- 3.10.20, 3.11.0 - 3.11.15, 3.12.0 - 3.12.13, 3.13.0 - 3.13.11, 3.14.0, 3.15.0
As listed in the NVD configuration data. Not a statement about your estate.
References
- https://github.com/python/cpython/commit/14b1fdb0a94b96f86fc7b86671ea9582b8676628
- https://github.com/python/cpython/commit/289f29b0fe38baf2d7cb5854f4bb573cc34a6a15
- https://github.com/python/cpython/commit/4ce27904b597c77d74dd93f2c912676021a99155
- https://github.com/python/cpython/commit/5a4c4a033a4a54481be6870aa1896fad732555b5
- https://github.com/python/cpython/commit/5dc101675fd22918facbbe0fecdc821502beaaf0
- https://github.com/python/cpython/commit/afc40bdd3dd71f343fd9016f6d8eebbacbd6587c
- https://github.com/python/cpython/issues/119451
- https://github.com/python/cpython/pull/119454
- https://mail.python.org/archives/list/security-announce@python.org/thread/OQ6G7MKRQIS3OAREC3HNG3D2DPOU34XO/