CVE-2026-7259

Description

In PHP versions 8.2.* before 8.2.31, 8.3.* before 8.3.31, 8.4.* before 8.4.21, and 8.5.* before 8.5.6, a mismatch between encoding lists in Oniguruma and mbfl leads to a NULL pointer dereference, resulting in a segmentation fault and denial of service. The vulnerability is exploitable when user-controlled input can influence the encoding passed to mb_regex_encoding().

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
php5	26.04 LTS resolute	Not in release
	25.10 questing	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	26.04 LTS resolute	Not in release
	25.10 questing	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Not in release
	16.04 LTS xenial	Not affected
php7.2	26.04 LTS resolute	Not in release
	25.10 questing	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Not in release
	18.04 LTS bionic	Not affected
php7.4	26.04 LTS resolute	Not in release
	25.10 questing	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Not in release
	20.04 LTS focal	Not affected
php8.1	26.04 LTS resolute	Not in release
	25.10 questing	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Fixed 8.1.2-1ubuntu2.24
php8.3	26.04 LTS resolute	Not in release
	25.10 questing	Not in release
	24.04 LTS noble	Fixed 8.3.6-0ubuntu0.24.04.9
	22.04 LTS jammy	Not in release
php8.4	26.04 LTS resolute	Not in release
	25.10 questing	Fixed 8.4.11-1ubuntu1.2
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Not in release
php8.5	26.04 LTS resolute	Fixed 8.5.4-0ubuntu1.1
	25.10 questing	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Not in release

Notes

sbeattie

PEAR issues should go against php-pear as of xenial

mdeslaur

per Debian, introduced in 8.0.0RC2 with: https://github.com/php/php-src/commit/73455778d4ae35110a987f1019e548aff721c3af

Patch details

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

Package	Patch details
php8.5	Upstream: 79a054e

Severity score breakdown

Parameter	Value
Base score	6.5 · Medium
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	Required
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

USN-8336-1
PHP vulnerabilities
28 May 2026

Cvss 3 Severity Score