PHP 8.4/8.5 (before 8.4.21/8.5.6) DOMNode::C14N() DoS via infinite loop
CVE-2026-7263 Published on May 10, 2026

DoS attack via DOMNode::C14N()
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.

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-7263 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Weakness Types

Improper Resource Shutdown or Release

The program does not release or incorrectly releases a resource before it is made available for re-use. When a resource is created or allocated, the developer is responsible for properly releasing the resource as well as accounting for all potential paths of expiration or invalidation, such as a set period of time or revocation.

What is an Infinite Loop Vulnerability?

The program contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. If the loop can be influenced by an attacker, this weakness could allow attackers to consume excessive resources such as CPU or memory.

CVE-2026-7263 has been classified to as an Infinite Loop vulnerability or weakness.


Products Associated with CVE-2026-7263

You can be notified by email with stack.watch whenever vulnerabilities like CVE-2026-7263 are published in these products:

PHP
 
Canonical Ubuntu Linux
 
Red Hat Enterprise Linux (RHEL)
 
Red Hat Hummingbird
 

Affected Versions

PHP Group PHP: Red Hat Enterprise Linux AppStream (v. 10): Red Hat Enterprise Linux 10: Red Hat Enterprise Linux 6: Red Hat Enterprise Linux 7: Red Hat Enterprise Linux 8: Red Hat Enterprise Linux 9: Red Hat Hardened Images:

Exploit Probability

EPSS
0.27%
Percentile
18.25%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.