CVE-2025-13836
Published: December 3, 2025Last modified: January 15, 2026
Description
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 9.1 |
| Attack Vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | python3 | Fixed (3.11.13-r2) |
| 25 LTS | python3 | Fixed (3.12.12-r1) | |
| Stream | python3 | Fixed (3.12.12-r2) | |
| Hardened Containers | 23 LTS | python3 | Fixed (3.11.13-r2) |
| 25 LTS | python3 | Fixed (3.12.12-r1) | |
| Stream | python3 | Fixed (3.12.12-r2) |
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/[email protected]/thread/OQ6G7MKRQIS3OAREC3HNG3D2DPOU34XO/