CVE-2025-13836

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. 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.

9.1 /10

CVSS v3 : CRITICAL

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://github.com/python/cpython/commit/14b1fdb0a94b96f86fc7b86671ea9582b8676628 Patch
https://github.com/python/cpython/commit/289f29b0fe38baf2d7cb5854f4bb573cc34a6a15 Patch
https://github.com/python/cpython/commit/4ce27904b597c77d74dd93f2c912676021a99155 Patch
https://github.com/python/cpython/commit/5a4c4a033a4a54481be6870aa1896fad732555b5 Patch
https://github.com/python/cpython/commit/5dc101675fd22918facbbe0fecdc821502beaaf0
https://github.com/python/cpython/commit/afc40bdd3dd71f343fd9016f6d8eebbacbd6587c
https://github.com/python/cpython/issues/119451 Issue Tracking Patch
https://github.com/python/cpython/pull/119454 Issue Tracking Patch
https://mail.python.org/archives/list/security-announce@python.org/thread/OQ6G7MKRQIS3OAREC3HNG3D2DPOU34XO/ Vendor Advisory
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:python:python:*:*:*:*:*:*:*:*
cpe:2.3:a:python:python:3.14.0:-:*:*:*:*:*:*
cpe:2.3:a:python:python:3.15.0:alpha1:*:*:*:*:*:*
cpe:2.3:a:python:python:3.15.0:alpha2:*:*:*:*:*:*
History

26 Jan 2026, 15:16

Type Values Removed Values Added
References
  • () https://github.com/python/cpython/commit/5dc101675fd22918facbbe0fecdc821502beaaf0 -
  • () https://github.com/python/cpython/commit/afc40bdd3dd71f343fd9016f6d8eebbacbd6587c -
Summary
  • (es) Al leer una respuesta HTTP de un servidor, si no se especifica una cantidad de lectura, el comportamiento predeterminado será usar Content-Length. Esto permite a un servidor malicioso hacer que el cliente lea grandes cantidades de datos en la memoria, lo que podría causar OOM u otro DoS.

30 Dec 2025, 15:08

Type Values Removed Values Added
References () https://github.com/python/cpython/commit/14b1fdb0a94b96f86fc7b86671ea9582b8676628 - () https://github.com/python/cpython/commit/14b1fdb0a94b96f86fc7b86671ea9582b8676628 - Patch
References () https://github.com/python/cpython/commit/289f29b0fe38baf2d7cb5854f4bb573cc34a6a15 - () https://github.com/python/cpython/commit/289f29b0fe38baf2d7cb5854f4bb573cc34a6a15 - Patch
References () https://github.com/python/cpython/commit/4ce27904b597c77d74dd93f2c912676021a99155 - () https://github.com/python/cpython/commit/4ce27904b597c77d74dd93f2c912676021a99155 - Patch
References () https://github.com/python/cpython/commit/5a4c4a033a4a54481be6870aa1896fad732555b5 - () https://github.com/python/cpython/commit/5a4c4a033a4a54481be6870aa1896fad732555b5 - Patch
References () https://github.com/python/cpython/issues/119451 - () https://github.com/python/cpython/issues/119451 - Issue Tracking, Patch
References () https://github.com/python/cpython/pull/119454 - () https://github.com/python/cpython/pull/119454 - Issue Tracking, Patch
References () https://mail.python.org/archives/list/security-announce@python.org/thread/OQ6G7MKRQIS3OAREC3HNG3D2DPOU34XO/ - () https://mail.python.org/archives/list/security-announce@python.org/thread/OQ6G7MKRQIS3OAREC3HNG3D2DPOU34XO/ - Vendor Advisory
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 9.1
CPE cpe:2.3:a:python:python:3.14.0:-:*:*:*:*:*:*
cpe:2.3:a:python:python:3.15.0:alpha2:*:*:*:*:*:*
cpe:2.3:a:python:python:3.15.0:alpha1:*:*:*:*:*:*
cpe:2.3:a:python:python:*:*:*:*:*:*:*:*
CWE CWE-125
First Time Python
Python python

22 Dec 2025, 20:15

Type Values Removed Values Added
References
  • () https://github.com/python/cpython/commit/14b1fdb0a94b96f86fc7b86671ea9582b8676628 -

05 Dec 2025, 17:16

Type Values Removed Values Added
References
  • () https://github.com/python/cpython/commit/289f29b0fe38baf2d7cb5854f4bb573cc34a6a15 -

02 Dec 2025, 19:15

Type Values Removed Values Added
CWE CWE-400

02 Dec 2025, 18:15

Type Values Removed Values Added
References
  • () https://mail.python.org/archives/list/security-announce@python.org/thread/OQ6G7MKRQIS3OAREC3HNG3D2DPOU34XO/ -

01 Dec 2025, 19:15

Type Values Removed Values Added
References
  • () https://github.com/python/cpython/commit/4ce27904b597c77d74dd93f2c912676021a99155 -
  • () https://github.com/python/cpython/commit/5a4c4a033a4a54481be6870aa1896fad732555b5 -

01 Dec 2025, 18:16

Type Values Removed Values Added
New CVE
Information

Published : 2025-12-01 18:16

Updated : 2026-01-26 15:16

NVD link : CVE-2025-13836

Mitre link : CVE-2025-13836

CVE.ORG link : CVE-2025-13836

JSON object : View

Products Affected

python

  • python
CWE
CWE-125

Out-of-bounds Read

CWE-400

Uncontrolled Resource Consumption