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Vulnerability record · CVE-2025-6491 · published 13 July 2025

CVE-2025-6491: Php null pointer dereference vulnerability

Php · Php

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.

5.9 CVSS 3.1 Medium EPSS 0.97% · top 39.4% CWE-476 · NULL pointer dereference
5.9CVSS 3.1 base score
0.97%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

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.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/php/php-src/security/advisories/GHSA-453j-q27h-5p8x ExploitVendor Advisory
http://www.openwall.com/lists/oss-security/2025/07/11/4
https://lists.debian.org/debian-lts-announce/2025/07/msg00017.html
https://github.com/php/php-src/security/advisories/GHSA-453j-q27h-5p8x ExploitVendor Advisory

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2025-6491), CISA KEV, FIRST EPSS (scores of 2026-09-29). This page is refreshed as NVD updates the record.