Threat Intelligence / CVE / CVE-2026-91769

CVE-2026-91769 — PHP

CVSS v3.1 4.3 (MEDIUM) · Priority 2.2/10 · Published 2026-09-25

As of 2026-09-25, CVE-2026-91769 is a MEDIUM-severity vulnerability in PHP, CVSS v3.1 4.3. Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-91769, 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-2026-91769?

PHP's OpenSSL stream peer verification checks the certificate's subjectAltName entries first and, whenever no entry matches, falls back to the Common Name. RFC 6125 requires the CN to be ignored once the certificate presents any service identity, so a certificate carrying a non-matching DNS SAN was still accepted when its CN matched the requested peer_name. A certificate trusted by the client for one name can therefore be used to impersonate another.

The record classifies CVE-2026-91769 under weakness class CWE-297. Its CVSS v3 base vector states that the flaw is reachable from an adjacent network, needs no prior authentication, needs no user interaction. 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: 4.3 — MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CISA KEV: Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority: 2.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published: 2026-09-25

Is CVE-2026-91769 being exploited?

No public exploitation evidence for CVE-2026-91769 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-2026-91769

No vendor patch reference has been recorded for CVE-2026-91769 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-2026-91769

1 tracked threat in the Threadlinqs corpus references CVE-2026-91769, 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-2026-91769 are available via the Threadlinqs MCP server (Purple tier). View plans →

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