CVE Tools
Sign in

CVE-2025-13836

Excessive read buffering DoS in http.client

Published: Dec 1, 2025Updated: May 18, 2026 Sources: CVE List NVD BDUCWE-400
NVD MITRE
7.5CVSSHIGH
EPSS Score
1.5%
Top 29.7%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

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.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:NI:NA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-400

Affected Products

CPythonPython Software FoundationOSS Libraries
pythonpythonOSS Libraries
Red Hat Enterprise LinuxRed Hat Inc.
On-premOS
Operating Systems / linux-distro
OpenShift Dev SpacesRed Hat Inc.
SaaSSaaS Service
Cloud & SaaS / container-orchestration
АЛЬТ СП 10АО «ИВК»
On-premOS
Operating Systems / linux-distro
python software foundationoss-projectUSOSS Librariesaka python software foundation, psf
pythonoss-projectUSOSS Libraries
red hat inc.commercialUSOperating Systemsaka red hat
ао «ивк»commercialRUOperating Systemsaka ivk
and 6 more affected products View all →

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

Official Patch Available

MITRE ATT&CK

1 technique
Impact
View detailed technique mapping

References

https://github.com/python/cpython/issues/119451
github.com
https://github.com/python/cpython/pull/119454
github.com
https://github.com/python/cpython/commit/4ce27904b597c77d74dd93f2c912676021a99155
github.com
and 10 more references View all →

Timeline

Published
Dec 1, 2025
Last Updated
May 18, 2026

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2025-13836 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
Plain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows