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TI-2025-05892 Aliases CVE-2025-6491

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

Priority MEDIUM 60CWE-476Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 2 fixed, 4 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-476.

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.01117 66th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial PHP (PHP Group): 8.1.33, 8.2.29, 8.3.23 +1Red Hat: 4 advisoriesRed Hat: 2 fixed, 4 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
PHP GroupPHPbefore 8.1.33; before 8.2.29; before 8.3.23; before 8.4.108.1.33, 8.2.29, 8.3.23, 8.4.10Patch availableCNA
  • PHP VendorPHP Group Affected before 8.1.33; before 8.2.29; before 8.3.23; before 8.4.10 Fixed in 8.1.33, 8.2.29, 8.3.23, 8.4.10 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:php:php:*:*:*:*:*:*:*:*8.1.0 to before 8.1.33; 8.2.0 to before 8.2.29; 8.3.0 to before 8.3.23; 8.4.0 to before 8.4.10VulnerablePHP
  • cpe:2.3:a:php:php:*:*:*:*:*:*:*:* Versions 8.1.0 to before 8.1.33; 8.2.0 to before 8.2.29; 8.3.0 to before 8.3.23; 8.4.0 to before 8.4.10 Vulnerable ·PHP

Remediation

  • Fix · CNA PHP (PHP Group) Fixed in 8.1.33, 8.2.29, 8.3.23, 8.4.10

Red Hat 4 advisories

  • RHSA-2026:2470 Released 2026-02-10 · Red Hat rating Moderate
    php:7.4 security update
    • Red Hat Enterprise Linux AppStream (v. 8) apcu-panel-5.1.18-1.module+el8.10.0+22485+a3539972.noarch::php:7.4, libzip-1.6.1-1.module+el8.10.0+22485+a3539972.aarch64::php:7.4, libzip-1.6.1-1.module+el8.10.0+22485+a3539972.ppc64le::php:7.4 +47
  • RHSA-2026:1409 Released 2026-01-27 · Red Hat rating Important
    php:8.2 security update
    • Red Hat Enterprise Linux AppStream (v. 9) apcu-panel-5.1.23-1.module+el9.4.0+20748+b46899d2.noarch::php:8.2, php-8.2.30-1.module+el9.7.0+23849+7b831f17.aarch64::php:8.2, php-8.2.30-1.module+el9.7.0+23849+7b831f17.ppc64le::php:8.2 +47
  • RHSA-2026:1412 Released 2026-01-27 · Red Hat rating Important
    php:8.2 security update
    • Red Hat Enterprise Linux AppStream (v. 8) apcu-panel-5.1.23-1.module+el8.10.0+20770+a5eca186.noarch::php:8.2, libzip-1.7.3-1.module+el8.10.0+20770+a5eca186.aarch64::php:8.2, libzip-1.7.3-1.module+el8.10.0+20770+a5eca186.ppc64le::php:8.2 +47
Show 1 more Red Hat advisories
  • RHSA-2025:23309 Released 2025-12-18 · Red Hat rating Moderate
    php:8.3 security update
    • Red Hat Enterprise Linux AppStream (v. 9) apcu-panel-5.1.23-1.module+el9.6.0+22647+1741ae35.noarch::php:8.3, php-8.3.26-1.module+el9.7.0+23549+c13c2ce3.aarch64::php:8.3, php-8.3.26-1.module+el9.7.0+23549+c13c2ce3.ppc64le::php:8.3 +47

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    PHP 8.1.33, 8.2.29 and 2 more versions

    3 records Highest priority Priority MEDIUM 2 MEDIUM, 1 LOW

    Other records, highest priority first

    • TI-2025-01044 Null byte termination in hostnamesPriority MEDIUM 57
    • TI-2025-01493 pgsql extension does not check for errors during escapingPriority LOW 35
    Show all 3 records →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 6AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 7AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:1412, RHSA-2026:2470
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2025:23309, RHSA-2026:1409

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-6491

References

Exploit 1

  • TI-2024-04260 Argument Injection in PHP-CGI KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-78794 PHP remote code execution via stale global state KEVCVSS 4.0CRITICAL 9.2
  • TI-2026-78793 Out-of-memory handling flaw in PHP allows remote code execution KEVCVSS 4.0CRITICAL 9.2
  • TI-2024-01743 Command injection via array-ish $command parameter of proc_open() CVSS 3.1CRITICAL 9.4
  • TI-2022-13555 PDO::quote() may return unquoted string CVSS 3.1CRITICAL 9.1
  • TI-2024-10408 Reference counting in php_request_shutdown causes Use-After-Free CVSS 4.0CRITICAL 9.2
See all 107 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences