What is CVE-2026-91765?
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.
The record classifies CVE-2026-91765 under weakness class CWE-674. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 49 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 7.5 — HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 3.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-09-25
Is CVE-2026-91765 being exploited?
No public exploitation evidence for CVE-2026-91765 is recorded in the sources Threadlinqs tracks — CISA KEV, Exploit-DB, public proof-of-concept repositories and ProjectDiscovery Nuclei — as of 2026-09-25. That is an absence of evidence in those feeds, not a guarantee that the vulnerability is unexploited.
Affected products and versions
- PHP Group: PHP
How to fix CVE-2026-91765
Vendor advisory: https://github.com/php/php-src/security/advisories/GHSA-rgrp-mwpx-f6rm. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.
Threat activity tracking CVE-2026-91765
1 tracked threat in the Threadlinqs corpus references CVE-2026-91765, either in the campaign’s CVE list or as an indicator on the campaign record.
Sources
Enriched from CVE.org, NVD. This product uses the NVD API but is not endorsed or certified by the NVD.