CVE-2026-91768
published 2026-09-25CVE-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…
PriorityP432medium6.5CVSS 3.1
AVAACLPRNUINSUCHINAN
EPSS
0.38%
31.4th percentile
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
17 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | php8.4 | — | — |
| php | php | — | — |
| php_7.4 | php | — | — |
| php_8.2 | php | — | — |
| php_8.3 | php | — | — |
| php_8.4 | php | — | — |
| php_group | php | >= 8.2.* < 8.2.34 | 8.2.34 |
| php_group | php | >= 8.3.* < 8.3.35 | 8.3.35 |
| php_group | php | >= 8.4.* < 8.4.26 | 8.4.26 |
| php_group | php | >= 8.5.* < 8.5.11 | 8.5.11 |
| ubuntu | php5 | — | — |
| ubuntu | php7.0 | — | — |
| ubuntu | php7.2 | — | — |
| ubuntu | php7.4 | — | — |
| ubuntu | php8.1 | — | — |
| ubuntu | php8.3 | — | — |
| ubuntu | php8.5 | — | — |
CVSS provenance
nvdv3.16.5MEDIUMCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
vendor_redhat6.5MEDIUM
vendor_ubuntu3.4LOW
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Ubuntu
PHP vulnerabilities
vendor_ubuntu·2026-10-19·CVSS 3.4
CVE-2026-93682 [LOW] PHP vulnerabilities
Title: PHP vulnerabilities
Summary: Several security issues were fixed in PHP.
It was discovered that PHP did not properly validate the size of MySQL
server packets in the mysqlnd driver. A malicious server could possibly use
this issue to cause PHP to crash, resulting in a denial of service. This
issue was only addressed in Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu
24.04 LTS, Ubuntu 26.04 LTS, and Ubuntu 26.10. (CVE-2025-1218)
It was discovered that PHP incorrectly handled response buffer sizes in the
SOAP HTTP client. A malicious server could possibly use this issue to cause
PHP to crash, resulting in a denial of service, or execute arbitrary code.
(CVE-2025-14181)
It was discovered that PHP incorrectly handled certain TAR archive headers
in the Phar extension. An attacker could pos
Red Hat
php: php: Access control bypass via partial IPv6 address comparison
vendor_redhat·2026-09-25·CVSS 6.5
CVE-2026-91768 [MEDIUM] CWE-940 php: php: Access control bypass via partial IPv6 address comparison
php: php: Access control bypass via partial IPv6 address comparison
A flaw was found in PHP. The access control check for Internet Protocol version 6 (IPv6) addresses in the FastCGI implementation compares only the first 12 bytes of a 16-byte address instead of the complete address. An attacker on an adjacent network with an address sharing the first 96 bits with an authorized client can bypass network access restrictions to reach the FastCGI endpoint, potentially leading to unauthorized information disclosure.
Package: php (Red Hat Enterprise Linux 10) - Fix deferred
Package: php8.4 (Red Hat Enterprise Linux 10) - Fix deferred
Package: php (Red Hat Enterprise Linux 6) - Out of support scope
Package: php (Red Hat Enterprise Linux 7) - Fix deferred
Package: php:7.4/php (Red Hat Enterp
VulDB
PHP up to 8.2.33/8.3.34/8.4.25/8.5.10 FastCGI Access Check comparison
vuldb·2026-09-25·CVSS 6.5
CVE-2026-91768 [MEDIUM] PHP up to 8.2.33/8.3.34/8.4.25/8.5.10 FastCGI Access Check comparison
A vulnerability classified as critical was found in PHP up to 8.2.33/8.3.34/8.4.25/8.5.10. This issue affects some unknown processing of the component FastCGI Access Check. Such manipulation leads to incorrect comparison.
This vulnerability is referenced as CVE-2026-91768. It is possible to launch the attack remotely. No exploit is available.
Upgrading the affected component is advised.
No detection rules found.
No public exploits indexed.
2026-09-25
Published