TLS Hostname Verification Falls Back to CN After SAN Mismatch

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

not scored

EPSS

• CVE-2026-91769: 0.16% estimated exploitation activity in the next 30 days; percentile 5.10 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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.

Published by the source

1 Oct 2026, 09:34 UTC

Last modified by the source

26 Oct 2026, 08:45 UTC

Source last checked

26 Oct 2026, 12:50 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from osv record BIT-libphp-2026-91769

2. Revision 2 · amended · 26 Oct 2026

   Amended from osv record BIT-php-min-2026-91769

3. Revision 1 · created · 26 Oct 2026

   Published from osv record BIT-php-2026-91769

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# Patch Next advisory brief: CVE-2026-91769

Advisory: TLS Hostname Verification Falls Back to CN After SAN Mismatch
IDs: CVE-2026-91769
Record: https://patchnext.com/advisories/cve-2026-91769 (revision 3, source checked 26 Oct 2026, 12:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: php 8.5.11, 8.4.26, 8.3.35, 8.2.34; libphp 8.5.11, 8.4.26, 8.3.35, 8.2.34; php-min 8.5.11, 8.4.26, 8.3.35, 8.2.34. A vendor fix does not mean a deployment is fixed.

## Affected components
- Bitnami php: affected >= 8.2.0, < 8.2.34; >= 8.3.0, < 8.3.35; >= 8.4.0, < 8.4.26; >= 8.5.0, < 8.5.11; fixed in 8.3.35, 8.5.11, 8.4.26, 8.2.34
- Bitnami libphp: affected >= 8.2.0, < 8.2.34; >= 8.3.0, < 8.3.35; >= 8.4.0, < 8.4.26; >= 8.5.0, < 8.5.11; fixed in 8.3.35, 8.5.11, 8.4.26, 8.2.34
- Bitnami php-min: affected >= 8.2.0, < 8.2.34; >= 8.3.0, < 8.3.35; >= 8.4.0, < 8.4.26; >= 8.5.0, < 8.5.11; fixed in 8.3.35, 8.5.11, 8.4.26, 8.2.34

## Suggested inspection (read-only)
- Bitnami php: check the installed version with your package manager.
- Bitnami libphp: check the installed version with your package manager.
- Bitnami php-min: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on php, libphp, php-min.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/BIT-php-2026-91769 (OSV record BIT-php-2026-91769 lists affected ranges: Bitnami php >=8.2.0 =8.3.0 =8.4.0 =8.5.0 <8.5.11 (fixed))
- Verified: https://osv.dev/vulnerability/BIT-php-min-2026-91769 (OSV record BIT-php-min-2026-91769 lists affected ranges: Bitnami php-min >=8.2.0 =8.3.0 =8.4.0 =8.5.0 <8.5.11 (fixed))
- Verified: https://osv.dev/vulnerability/BIT-libphp-2026-91769 (OSV record BIT-libphp-2026-91769 lists affected ranges: Bitnami libphp >=8.2.0 =8.3.0 =8.4.0 =8.5.0 <8.5.11 (fixed))

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