Threat Intelligence / CVE / CVE-2026-91765

CVE-2026-91765 — PHP

CVSS v3.1 7.5 (HIGH) · Priority 3.8/10 · Published 2026-09-25

As of 2026-09-25, CVE-2026-91765 is a HIGH-severity vulnerability in PHP, CVSS v3.1 7.5. Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-91765, most recently “Multiple PHP Vulnerabilities Enable Denial of Service, TLS Verification Bypass, and Credential Leakage (CVE-2026-91765, CVE-2026-91768, CVE-2026-6103 and 8 Others) — GovCERT.HK A26-09-40”.

Last updated: 2026-09-25

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 1 day 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

No vendor patch reference has been recorded for CVE-2026-91765 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

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.

Multiple PHP Vulnerabilities Enable Denial of Service, TLS Verification Bypass, and Credential Leakage (CVE-2026-91765, CVE-2026-91768, CVE-2026-6103 and 8 Others) — GovCERT.HK A26-09-40 — MEDIUM · 2026-09-25

Sources

Enriched from CVE.org, NVD. Last verified by Threadlinqs on 2026-09-26. This product uses the NVD API but is not endorsed or certified by the NVD.

Vendor advisory and patch

github.com — vendor advisory

Full detection coverage & IOCs for threats exploiting CVE-2026-91765 are available via the Threadlinqs MCP server (Purple tier). View plans →

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