Bug 2541660 (CVE-2026-91768) - CVE-2026-91768 php: php: Access control bypass via partial IPv6 address comparison
Summary: CVE-2026-91768 php: php: Access control bypass via partial IPv6 address compa...
Keywords:
Status: NEW
Alias: CVE-2026-91768
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-25 21:21 UTC by OSIDB Bzimport
Modified: 2026-09-25 21:27 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:

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Description OSIDB Bzimport 2026-09-25 21:21:47 UTC 
The IPv6 branch of the FastCGI client access check compares only the first 12 bytes of a 16-byte IPv6 address, so listen.allowed_clients matches on a /96 prefix instead of the exact address. An attacker who can source an address sharing the first 96 bits with an allowed one passes the check and reaches the FastCGI endpoint.
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