CVE-2025-13836

medium

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.

References

https://mail.python.org/archives/list/[email protected]/thread/OQ6G7MKRQIS3OAREC3HNG3D2DPOU34XO/

https://github.com/python/cpython/pull/119454

https://github.com/python/cpython/issues/119451

https://github.com/python/cpython/commit/5a4c4a033a4a54481be6870aa1896fad732555b5

https://github.com/python/cpython/commit/4ce27904b597c77d74dd93f2c912676021a99155

https://github.com/python/cpython/commit/289f29b0fe38baf2d7cb5854f4bb573cc34a6a15

https://github.com/python/cpython/commit/14b1fdb0a94b96f86fc7b86671ea9582b8676628

Details

Source: Mitre, NVD

Published: 2025-12-01

Updated: 2025-12-30

Risk Information

CVSS v2

Base Score: 9.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:N/A:C

Severity: High

CVSS v3

Base Score: 9.1

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Severity: Critical

CVSS v4

Base Score: 6.3

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L

Severity: Medium

EPSS

EPSS: 0.00042