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CVE-2026-91768

medium

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…

Vendor / product: Php — php

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.

CVSS
6.5
6.5 (CVSS v3.1)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Severity source: NVD CVSS v3.1 (security@php.net)
Timeline (UTC)
Published: 2026-09-25 22:18
Modified: 2026-10-27 15:40
NVD status: Analyzed
Last synced 1 day ago
Verified against the source API 2026-10-28 11:30 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

php / php ≥8.2.0 <8.2.34, ≥8.3.0 <8.3.35, ≥8.4.0 <8.4.26, ≥8.5.0 <8.5.11

Weakness classification (CWE)

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

Vendor advisory: https://github.com/php/php-src/security/advisories/GHSA-62xp-839h-2637

References

Data sources

NVD CVE API 2.0 — fetched 2026-10-28 11:30 UTC · record ↗

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