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.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00188.

Exploitation poc

Automatable no

Technical Impact partial

Affected Vendors & Products

Vendors Products
Php
  • Php

Configuration 1 [-]

OR cpe:2.3:a:php:php:*:*:*:*:*:*:*:*
cpe:2.3:a:php:php:*:*:*:*:*:*:*:*
cpe:2.3:a:php:php:*:*:*:*:*:*:*:*
cpe:2.3:a:php:php:*:*:*:*:*:*:*:*

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

Vendors Products
Php
  • Php
Advisories
Source ID Title
Debian DLA Debian DLA DLA-4254-1 php7.4 security update
Debian DSA Debian DSA DSA-5967-1 php8.2 security update
EUVD EUVD EUVD-2025-21276 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.
Ubuntu USN Ubuntu USN USN-7648-1 PHP vulnerabilities
Ubuntu USN Ubuntu USN USN-7648-2 PHP vulnerabilities
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
http://www.openwall.com/lists/oss-security/2025/07/11/4 cve-icon
https://github.com/php/php-src/security/advisories/GHSA-453j-q27h-5p8x cve-icon cve-icon cve-icon cve-icon
https://lists.debian.org/debian-lts-announce/2025/07/msg00017.html cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2025-6491 cve-icon
https://www.cve.org/CVERecord?id=CVE-2025-6491 cve-icon
History

Tue, 04 Nov 2025 22:30:00 +0000

Type Values Removed Values Added
References

Mon, 03 Nov 2025 20:30:00 +0000

Type Values Removed Values Added
References

Tue, 22 Jul 2025 17:00:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:php:php:*:*:*:*:*:*:*:*

Wed, 16 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.0006}

 epss

{'score': 0.00081}

Mon, 14 Jul 2025 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Mon, 14 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.0006}

Sun, 13 Jul 2025 22:15:00 +0000

Type Values Removed Values Added
Description A vulnerability was found in PHP. If a SoapVar instance is created with a fully qualified name larger than 2G, this will cause a NULL pointer dereference resulting in a segmentation fault, leading to a denial of service. 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.
Title php: NULL Pointer Dereference in PHP SOAP Extension via Large XML Namespace Prefix NULL Pointer Dereference in PHP SOAP Extension via Large XML Namespace Prefix
Metrics epss

{}

Wed, 09 Jul 2025 00:30:00 +0000

Type Values Removed Values Added
Description A vulnerability was found in PHP. If a SoapVar instance is created with a fully qualified name larger than 2G, this will cause a NULL pointer dereference resulting in a segmentation fault, leading to a denial of service.
Title php: NULL Pointer Dereference in PHP SOAP Extension via Large XML Namespace Prefix
Weaknesses CWE-476
References
Metrics threat_severity

None

 cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate
cve-icon MITRE

Status: PUBLISHED

Assigner: php

Published:

Updated: 2025-11-04T21:14:48.898Z

Reserved: 2025-06-22T03:05:22.008Z

Link: CVE-2025-6491

cve-icon Vulnrichment

Updated: 2025-11-04T21:14:48.898Z

cve-icon NVD

Status : Modified

Published: 2025-07-13T22:15:23.353

Modified: 2025-11-04T22:16:43.147

Link: CVE-2025-6491

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-07-05T00:00:00Z

Links: CVE-2025-6491 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-07-14T22:45:28Z