CVE-2026-91769

MEDIUMPre-NVD 4.34.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 4.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1% (2nd percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 3 sources updated this week
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 4.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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.

CVSS v3
4.3
EG Score
4.3MEDIUMmedium confidence
EG Risk
19
EG Risk 19/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity43% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.1%
EPSS %ILE
2nd
KEV
Not listed

CISA SSVCTrack at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 25, 2026

Last Modified

September 29, 2026

Advisory Details (1)

Auto-updated Sep 25, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

TLS Hostname Verification Falls Back to CN After SAN Mismatch · Advisory · php/php-src · GitHub

https://github.com/php/php-src/security/advisories/GHSA-vvx9-73fr-5jjx

Vendor Advisories for CVE-2026-91769(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatphp-main-8.5.11-2.hum12026-09-23redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 19× in last 7d / 24× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-03 16:32 UTCEG score recompute
  2. 2026-10-03 16:32 UTCVendor advisory
  3. 2026-10-02 17:58 UTCEG score recompute
  4. 2026-10-02 17:58 UTCVendor advisory
  5. 2026-10-01 19:51 UTCEPSS rescore
  6. 2026-10-01 19:24 UTCVendor advisory
  7. 2026-09-30 20:49 UTCEG score recompute
  8. 2026-09-30 20:49 UTCVendor advisory
  9. 2026-09-30 15:04 UTCEPSS rescore
  10. 2026-09-29 22:16 UTCEG score recompute
  11. 2026-09-29 22:16 UTCVendor advisory
  12. 2026-09-29 13:00 UTCEG score recompute
  13. 2026-09-29 13:00 UTCVendor advisory
  14. 2026-09-28 14:26 UTCEG score recompute
  15. 2026-09-28 13:52 UTCEPSS rescore
  16. 2026-09-28 13:52 UTCEPSS rescore
  17. 2026-09-28 13:44 UTCEG score recompute
  18. 2026-09-27 18:28 UTCEG score recompute
  19. 2026-09-27 13:49 UTCEPSS rescore
  20. 2026-09-26 19:54 UTCEG score recompute
  21. 2026-09-26 15:59 UTCEPSS rescore
  22. 2026-09-25 21:18 UTCEG score recompute
  23. 2026-09-25 21:04 UTCEG score recompute
  24. 2026-09-25 21:04 UTCMITRE cvelistV5first tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-91769?
CVE-2026-91769 is a medium vulnerability published on September 25, 2026. 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…
When was CVE-2026-91769 disclosed?
CVE-2026-91769 was first published on September 25, 2026, with the most recent update on September 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-91769 actively exploited?
CVE-2026-91769 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (2nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-91769?
CVE-2026-91769 has a CVSS base score of 4.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-91769?
A fix for CVE-2026-91769 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-91769 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-91769

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