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CVE PROGRAM SOURCE RECORD6.5 Medium

CVE-2026-91768

IPv6 ACL bypass in FastCGI listen.allowed_clients due to partial address comparison (memcmp 12 bytes)

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Status
Published
Published
Updated
Assigning organization
php

Description

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

PHP Group PHP

Default version status: unaffected

  • 8.2.* to < 8.2.34affected
  • 8.3.* to < 8.3.35affected
  • 8.4.* to < 8.4.26affected
  • 8.5.* to < 8.5.11affected

References