CVE-2026-91768

Publication date 25 September 2026

Last updated 20 October 2026

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

6.5 · Medium

Score breakdown

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.

Read the notes from the security team

Status

Package Ubuntu Release Status
php5 26.10 stonking Not in release
26.04 LTS resolute Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
14.04 LTS trusty
Not affected
php7.0 26.10 stonking Not in release
26.04 LTS resolute Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
16.04 LTS xenial
Fixed in 7.0.33-0ubuntu0.16.04.16+esm21
php7.2 26.10 stonking Not in release
26.04 LTS resolute Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
18.04 LTS bionic
Fixed in 7.2.24-0ubuntu0.18.04.17+esm13
php7.4 26.10 stonking Not in release
26.04 LTS resolute Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
20.04 LTS focal
Fixed in 7.4.3-4ubuntu2.29+esm4
php8.1 26.10 stonking Not in release
26.04 LTS resolute Not in release
24.04 LTS noble Not in release
22.04 LTS jammy
Fixed in 8.1.2-1ubuntu2.27
php8.3 26.10 stonking Not in release
26.04 LTS resolute Not in release
24.04 LTS noble
Fixed in 8.3.6-0ubuntu0.24.04.12
22.04 LTS jammy Not in release
php8.5 26.10 stonking
Fixed in 8.5.9-0ubuntu2
26.04 LTS resolute
Fixed in 8.5.4-0ubuntu1.4
24.04 LTS noble Not in release
22.04 LTS jammy Not in release

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Notes

sbeattie

PEAR issues should go against php-pear as of xenial PEAR issues should go against php-pear as of xenial

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
php8.3
php8.5

Severity score breakdown

CVSS version: CVSS v3.0

Base score 6.5 · Medium

Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References

Related Ubuntu Security Notices (USN)

Other references

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