CVE-2026-91765 SOAP: Unbounded Recursion in Server-Side cleanup_xml_node

What is CVE-2026-91765?

CVE-2026-91765 is a high-severity denial of service vulnerability in Php Php, published on 25 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

cleanup_xml_node() in the SOAP XML parser recurses once per XML nesting level with no depth limit. An unauthenticated attacker can post a SOAP request containing tens of thousands of nested elements to any SoapServer endpoint, exhaust the stack and crash the process. The same unbounded recursion exists in the SOAP value decoder and in the WSDL node search helper.

Weakness: CWE-674

Which versions are affected by CVE-2026-91765?

3 open source packages ship an affected version, including libphp, php and php-min. It affects 1 product.

Products include Php Php.

How do I fix CVE-2026-91765?

Upgrade libphp to a fixed version for your release line: 8.2.34, 8.3.35, 8.4.26 or 8.5.11.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-91765 being exploited?

There is no known exploitation of CVE-2026-91765 in the wild and no public exploit code.

Other vulnerabilities in Php Php

• CVE-2012-2688 Integer overflow in n/a Critical 10.0
• CVE-2012-2376 Memory corruption in n/a Critical 10.0
• CVE-2011-3268 Memory corruption in n/a Critical 10.0
• CVE-2009-4143 Other in n/a Critical 10.0
• CVE-2008-5557 Memory corruption in n/a Critical 10.0

All Php Php vulnerabilities

Sources

• CVE record
• NVD
• OSV
• How this page is made

Also known as AZL-104919, BELL-CVE-2026-91765, BIT-libphp-2026-91765, BIT-php-2026-91765, BIT-php-min-2026-91765, CLEANSTART-2026-PP41218 and 11 more.