Medium severity · published Jul 13, 2025
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 SOAP extensions, overly large (>2Gb) XML namespace…
5.9
CVSS
1.1%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.1% · higher than 66% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PH
PHP · PHP
8.1.0 before 8.1.33; 8.2.0 before 8.2.29; 8.3.0 before 8.3.23; 8.4.0 before 8.4.10 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-6491
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-6491
Exploit
https://github.com/php/php-src/security/advisories/GHSA-453j-q27h-5p8x
www.openwall.com
http://www.openwall.com/lists/oss-security/2025/07/11/4
lists.debian.org
https://lists.debian.org/debian-lts-announce/2025/07/msg00017.html
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