// For flags

CVE-2025-13836

Excessive read buffering DoS in http.client

Severity Score

6.3
*CVSS v4

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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.

This update for python312 fixes the following issues. Quadratic complexity when building nested elements using 'xml.dom.minidom' methods that depend on '_clear_id_cache' can lead to availability issues when building excessively nested documents. Use of 'Content-Length' by default when reading an HTTP response with no read amount specified can lead to OOM issues and DoS when a client deals with a malicious server. Data read by the plistlib module according to the size specified by the file itself can lead to OOM issues and DoS.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
None
User Interaction
None
System
Vulnerable | Subsequent
Confidentiality
None
None
Integrity
None
None
Availability
Low
Low
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
None
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2025-12-01 CVE Reserved
  • 2025-12-01 CVE Published
  • 2026-03-03 CVE Updated
  • 2026-05-13 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-400: Uncontrolled Resource Consumption
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Python Software Foundation
Search vendor "Python Software Foundation"
 CPython
Search vendor "Python Software Foundation" for product "CPython"
 < 3.10.20
Search vendor "Python Software Foundation" for product "CPython" and version " < 3.10.20"
en
Affected
Python Software Foundation
Search vendor "Python Software Foundation"
 CPython
Search vendor "Python Software Foundation" for product "CPython"
 >= 3.11.0 < 3.11.15
Search vendor "Python Software Foundation" for product "CPython" and version " >= 3.11.0 < 3.11.15"
en
Affected
Python Software Foundation
Search vendor "Python Software Foundation"
 CPython
Search vendor "Python Software Foundation" for product "CPython"
 >= 3.12.0 < 3.12.13
Search vendor "Python Software Foundation" for product "CPython" and version " >= 3.12.0 < 3.12.13"
en
Affected
Python Software Foundation
Search vendor "Python Software Foundation"
 CPython
Search vendor "Python Software Foundation" for product "CPython"
 >= 3.13.0 < 3.13.11
Search vendor "Python Software Foundation" for product "CPython" and version " >= 3.13.0 < 3.13.11"
en
Affected
Python Software Foundation
Search vendor "Python Software Foundation"
 CPython
Search vendor "Python Software Foundation" for product "CPython"
 >= 3.14.0 < 3.14.1
Search vendor "Python Software Foundation" for product "CPython" and version " >= 3.14.0 < 3.14.1"
en
Affected