CVE-2025-6491

Summary

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.

Impact & exploitability

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

Affected products we track (1)

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

Additional information

• NVD record
• https://github.com/php/php-src/security/advisories/GHSA-453j-q27h-5p8xAdvisory
• http://www.openwall.com/lists/oss-security/2025/07/11/4
• https://lists.debian.org/debian-lts-announce/2025/07/msg00017.html