CVE-2026-91766

CVE Details

Release Date:	2026-09-25
Impact:	Moderate	What is this?

Description

When the http:// stream wrapper follows a redirect it forwards the user-supplied Authorization, Cookie and Proxy-Authorization headers unchanged, even when the redirect target is a different host, a different port, or a downgrade from HTTPS to HTTP. A server that can steer a redirect therefore receives credentials that were only meant for the original origin. This is the same class of issue that libcurl fixed in 7.58.0 ( CVE-2018-1000007 https://github.com/advisories/GHSA-g7x2-hrfp-pv5f ).

See more information about CVE-2026-91766 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	5.9
Vector String:	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Version:	3.1
Attack Vector:	Network
Attack Complexity:	High
Privileges Required:	None
User Interaction:	None
Scope:	Unchanged
Confidentiality Impact:	High
Integrity Impact:	None
Availability Impact:	None

Errata information

Platform	Errata	Release Date
Oracle Linux version 8 (libzip)	ELSA-2026-87080	2026-10-21
Oracle Linux version 8 (php)	ELSA-2026-87080	2026-10-21
Oracle Linux version 8 (php-pear)	ELSA-2026-87080	2026-10-21
Oracle Linux version 8 (php-pecl-apcu)	ELSA-2026-87080	2026-10-21
Oracle Linux version 8 (php-pecl-rrd)	ELSA-2026-87080	2026-10-21
Oracle Linux version 8 (php-pecl-xdebug)	ELSA-2026-87080	2026-10-21
Oracle Linux version 8 (php-pecl-zip)	ELSA-2026-87080	2026-10-21