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CVE-2026-44431

urllib3: Sensitive headers forwarded across origins in proxied low-level redirects

Published: May 13, 2026Updated: Jun 26, 2026 Sources: CVE List NVDCWE-200
5.3MEDIUM
NVD MITRE
EPSS Score
0.3%
Top 74.3%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Workaround Only
Self-Check
OpenVAS

Description

urllib3 is an HTTP client library for Python. From 1.23 to before 2.7.0, cross-origin redirects followed from the low-level API via ProxyManager.connection_from_url().urlopen(..., assert_same_host=False) still forward these sensitive headers. This vulnerability is fixed in 2.7.0.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:LI:NA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:LConfidentiality
Low
I:NIntegrity
None
A:NAvailability
None
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Weaknesses

CWE-200NVD-CWE-noinfo

Affected Products

python
oss-project·US
urllib3
OSS Libraries
urllib3
oss-project
urllib3Library
OSS Libraries / pypi

Exploitability

Workaround Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Collection
View detailed technique mapping

References

https://github.com/urllib3/urllib3/security/advisories/GHSA-qccp-gfcp-xxvc
github.com
https://lists.debian.org/debian-lts-announce/2026/06/msg00040.html
lists.debian.org

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