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Vulnerabilities

Vulnerability · 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.

Published Sep 25, 2026 · catalog updated Oct 23, 2026 · PHP's OpenSSL stream peer

Last checked Oct 25, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-91769. EPSS is 0.15%. Act only if a listed version of PHP's OpenSSL stream peer is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (PHP's OpenSSL stream peer).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium4.3
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.15%
Remediation
Version ranges on file
Affected products
cpe php/php

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe php/php< 8.2.34
  • cpe php/php< 8.3.35
  • cpe php/php< 8.4.26
  • cpe php/php< 8.5.11

How to fix CVE-2026-91769

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-91769. EPSS is 0.15%. Act only if a listed version of PHP's OpenSSL stream peer is installed.

Which versions are affected?

Compare what you have installed with < 8.2.34, < 8.3.35, < 8.4.26, < 8.5.11. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-297. EPSS 0.15%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 25, 2026 · NIST NVD

    Detected

    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

  2. Oct 23, 2026 · NIST NVD

    Updated

    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

Sources

  • CVE.orgVulnerability recordCVE-2026-91769

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-91769

    30-day exploitation probability 0.15%

    first.org
  • NIST NVDVulnerability recordCVE-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-m

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 25, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSOct 25, 2026
  • CVE.orgOct 23, 2026
  • NIST NVDOct 23, 2026