NetSight
medium6.5

CVE-2026-91768

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 prefi…

Impact

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

VendorProductAffected versions
PhpPhp
from 8.2.0 before 8.2.34
from 8.3.0 before 8.3.35
from 8.4.0 before 8.4.26
from 8.5.0 before 8.5.11

Weakness classification

References