Vulnerability Monitor

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CVE-2026-91767


php_openssl_matches_wildcard_name() in ext/openssl/xp_ssl.c underflows the length argument passed to memchr() when a TLS server certificate presents a wildcard name whose literal characters are together longer than the hostname being verified. A malicious server presenting such a certificate makes the PHP client read up to SIZE_MAX bytes past the end of a heap allocation. The path is reachable from any default client stream, because verify_peer_name is enabled by default.


Security Impact Summary

This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 6.5, indicating it requires adjacent network access with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), for affected systems. Impacting 1 product from php organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2026, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.


Published

2026-09-25T21:17:24.793

Last Modified

2026-10-27T13:14:13.607

Status

Analyzed

Source

[email protected]

Severity

CVSSv3.1: 6.5 (MEDIUM)

Weaknesses
  • Type: Secondary
    CWE-122

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application php php < 8.2.34 Yes
Application php php < 8.3.35 Yes
Application php php < 8.4.26 Yes
Application php php < 8.5.11 Yes

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For php's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.