Home/CVE/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
CVE

CVE-2025-6491

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 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.

MEDIUM · CVSS 5.9 EPSS 0.00772
Schedule remediation
  • Public exploit or PoC is available
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-476NULL Pointer Dereference
▤

Affected Products & Versions

4
php>= 8.1.0 and < 8.1.33
php>= 8.2.0 and < 8.2.29
php>= 8.3.0 and < 8.3.23
php>= 8.4.0 and < 8.4.10
⚠

Public Exploits & PoCs

1
pocgithub.com · GHSA-453j-q27h-5p8xgithub.com
▣

Scoring & Timeline

5.9
MEDIUM · CVSS v3.1 · security@php.net
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD13 Jul 2025 · 10:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC triage · cisa-vulnrichment
Exploitation
poc
Automatable
no
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
⚑

Vendor Advisories

13
rhsaRHSA-2026:1412Low
rhsaRHSA-2026:1409Low
rhsaRHSA-2026:2470Low
msrcCVE-2025-6491
usnUSN-7648-2
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
http://www.openwall.com/lists/oss-security/2025/07/11/4
https://lists.debian.org/debian-lts-announce/2025/07/msg00017.html
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