CVE-2026-4366

MEDIUMPre-NVD 5.85.8—
EchelonGraph scoreMEDIUM confidence

Score 5.8 from GitHub Security Advisory published 2026-03-18. a secondary CVSS source baseline 5.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
5.8
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.8Exploit: NoneExposed: 0

A fix is available — apply it.

A flaw was identified in Keycloak, an identity and access management solution, where it improperly follows HTTP redirects when processing certain client configuration requests. This behavior allows an attacker to trick the server into making unintended requests to internal or restricted resources. As a result, sensitive internal services such as cloud metadata endpoints could be accessed. This issue may lead to information disclosure and enable attackers to map internal network infrastructure.

CVSS v3
5.8
EG Score
5.8(medium)
EPSS
13.5%
KEV
Not listed

Published

March 18, 2026

Last Modified

June 9, 2026

References (4)

Vendor Advisories for CVE-2026-4366(3)

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

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrhbk/keycloak-rhel9-operator:26.4-172026-05-20redhat
redhatpatch2026-05-20redhat

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 7× in last 7d / 37× 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. 2026-07-11 08:27 UTCEPSS rescore
  2. 2026-07-09 19:10 UTCEPSS rescore
  3. 2026-07-08 15:16 UTCEPSS rescore
  4. 2026-07-07 13:46 UTCEPSS rescore
  5. 2026-07-06 16:27 UTCEPSS rescore
  6. 2026-07-06 02:23 UTCEPSS rescore
  7. 2026-07-05 02:30 UTCEPSS rescore
  8. 2026-07-04 06:31 UTCEPSS rescore
  9. 2026-07-01 15:07 UTCEPSS rescore
  10. 2026-06-29 14:06 UTCEPSS rescore
  11. 2026-06-29 14:06 UTCEPSS rescore
  12. 2026-06-28 14:07 UTCEPSS rescore
  13. 2026-06-28 04:56 UTCEPSS rescore
  14. 2026-06-28 04:56 UTCEPSS rescore
  15. 2026-06-27 03:08 UTCEPSS rescore
  16. 2026-06-25 13:49 UTCEPSS rescore
  17. 2026-06-24 14:05 UTCEPSS rescore
  18. 2026-06-23 21:33 UTCEPSS rescore
  19. 2026-06-23 21:33 UTCEPSS rescore
  20. 2026-06-22 14:25 UTCEPSS rescore
  21. 2026-06-22 14:25 UTCEPSS rescore
  22. 2026-06-21 14:56 UTCEPSS rescore
  23. 2026-06-21 14:56 UTCEPSS rescore
  24. 2026-06-21 01:59 UTCEPSS rescore
  25. 2026-06-21 01:59 UTCEPSS rescore
Show 25 more
  1. 2026-06-19 19:26 UTCEPSS rescore
  2. 2026-06-19 19:26 UTCEPSS rescore
  3. 2026-06-18 17:52 UTCEPSS rescore
  4. 2026-06-18 17:52 UTCEPSS rescore
  5. 2026-06-17 17:53 UTCEPSS rescore
  6. 2026-06-16 17:53 UTCEPSS rescore
  7. 2026-06-15 17:49 UTCEPSS rescore
  8. 2026-06-15 17:49 UTCEPSS rescore
  9. 2026-06-14 23:18 UTCEPSS rescore
  10. 2026-06-13 23:00 UTCEPSS rescore
  11. 2026-06-12 23:12 UTCEPSS rescore
  12. 2026-06-12 23:12 UTCEPSS rescore
  13. 2026-06-11 23:52 UTCEG score recompute
  14. 2026-06-11 23:52 UTCVendor advisory
  15. 2026-06-11 23:52 UTCGHSA enrichment
  16. 2026-06-11 14:00 UTCEPSS rescore
  17. 2026-06-10 22:19 UTCEPSS rescore
  18. 2026-06-10 18:54 UTCEG score recompute
  19. 2026-06-10 18:54 UTCVendor advisory
  20. 2026-06-10 18:54 UTCGHSA enrichment
  21. 2026-06-10 13:22 UTCEPSS rescore
  22. 2026-06-10 13:22 UTCEPSS rescore
  23. 2026-06-09 17:24 UTCEG score recompute
  24. 2026-06-09 17:24 UTCGHSA enrichment
  25. 2026-06-09 17:17 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-4366?
CVE-2026-4366 is a medium vulnerability published on March 18, 2026. A flaw was identified in Keycloak, an identity and access management solution, where it improperly follows HTTP redirects when processing certain client configuration requests. This behavior allows an attacker to trick the server into making unintended requests to internal or restricted resources.…
When was CVE-2026-4366 disclosed?
CVE-2026-4366 was first published in the National Vulnerability Database on March 18, 2026, with the most recent update on June 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-4366 actively exploited?
CVE-2026-4366 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 13.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-4366?
CVE-2026-4366 has a CVSS v3 base score of 5.8 (NVD).
How do I remediate CVE-2026-4366?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-4366, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-4366

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