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CVE-2025-13836

Excessive read buffering DoS in http.client

Published: Dec 1, 2025Updated: May 18, 2026 Sources: CVE List NVD BDUCWE-400
7.5HIGH
NVD MITRE
EPSS Score
1.6%
Top 26.6%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
OpenVAS

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.

No summary for this CVE yet.

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
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Weaknesses

CWE-400

Affected Products

Red Hat Inc.
commercial·USaka red hat
Red Hat Enterprise LinuxOn-premOS
Operating Systems / linux-distro
OpenShift Dev SpacesOn-prem
Operating Systems / linux-distro
Red Hat DiscoveryOn-prem
Operating Systems / linux-distro
Red Hat Enterprise Linux AIOn-prem
Operating Systems / linux-distro
Red Hat Update InfrastructureOn-prem
Operating Systems / linux-distro
Python Software Foundation
oss-project·USaka psf
CPython
OSS Libraries
PythonLibraryLibrary
OSS Libraries
python
oss-project·US
pythonLibraryLibrary
OSS Libraries
АО «ИВК»
commercial·RUaka ivk
АЛЬТ СП 10On-premOS
Operating Systems / linux-distro
ООО «Ред Софт»
commercial·RUaka red soft
РЕД ОСOn-premOS
Operating Systems / linux-distro
АО «СберТех»
commercial·RUaka ao sbertech, сбертех
Platform V SberLinux OS ServerOn-premOS
Operating Systems / linux-distro

Exploitability

Official Patch Available
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Attack Graph

Products CVE Techniques Tactics

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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 →

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