CVE-2023-43804

`Cookie` HTTP header isn't stripped on cross-origin redirects

HIGH
8.1
CVSS Score
Published: October 4, 2023 at 04:01 PM UTC
Updated: June 17, 2026 at 06:26 AM UTC
4 products affected across 4 vendorsDebian LinuxFedoraURLLIB3

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Severity
HIGH8.1
Exploit prediction
EPSS 1%

Description

urllib3 is a user-friendly HTTP client library for Python. urllib3 doesn't treat the `Cookie` HTTP header special or provide any helpers for managing cookies over HTTP, that is the responsibility of the user. However, it is possible for a user to specify a `Cookie` header and unknowingly leak information via HTTP redirects to a different origin if that user doesn't disable redirects explicitly. This issue has been patched in urllib3 version 1.26.17 or 2.0.5.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.26.172.0.0 ≤ v < 2.0.6
Affected range stops below 1.26.17, so it looks safe — our inference, not a vendor statement
Affected range stops below 2.0.6, so it looks safe — our inference, not a vendor statement
v < 1.26.17v < 2.0.6
Affected range stops below 1.26.17, so it looks safe — our inference, not a vendor statement
Affected range stops below 2.0.6, so it looks safe — our inference, not a vendor statement

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-200NVD-CWE-noinfo

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