CVE-2026-7263

Description

In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, DOMNode::C14N() method may process the XML data incorrectly, causing a circular linked list in the data structure representing the XML document. This may cause subsequent processing of the XML document to enter infinite loop, causing denial of service in the processing application.

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	Not affected
php8.3	26.04 LTS resolute	Not in release
	25.10 questing	Not in release
	24.04 LTS noble	Not affected
	22.04 LTS jammy	Not in release
php8.4	26.04 LTS resolute	Not in release
	25.10 questing	Not affected
	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

only affects 8.4.0 and higher introduced by: https://github.com/php/php-src/commit/40c291cf932c31a302fa584bb50b6edb199fb07e

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: d43c523

Severity score breakdown

Parameter	Value
Base score	7.5 · High
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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