CVE-2025-6491

NULL Pointer Dereference in PHP SOAP Extension via Large XML Namespace Prefix

In PHP versions:8.1.* before 8.1.33, 8.2.* before 8.2.29, 8.3.* before 8.3.23, 8.4.* before 8.4.10 when parsing XML data in SOAP extensions, overly large (>2Gb) XML namespace prefix may lead to null pointer dereference. This may lead to crashes and affect the availability of the target server.

Affected

PHP Group · PHP

CVSS v3.1 PHP

5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.99% chance of exploitation in the next 30 days, 62nd percentile

Published

2025-07-13

Updated

2025-11-04

Proof-of-concept exploits (1)

• php/php-src/security/advisories/GHSA-453j-q27h-5p8x

References

• CVE Record
• NVD entry