CVE-2026-18211

MEDIUMNVD 5.45.4—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.4 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 92% of all CVEs by exploit prediction. GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
5.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.4Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

A flaw was found in the secure-client-uris client policy executor within Keycloak core services. This component is responsible for enforcing security requirements on client configurations, such as requiring encrypted connections for redirect URIs. Due to an improper check that only looks at the start of a web address rather than properly verifying the host, an attacker can bypass these security restrictions by using a specially crafted domain name. This could allow an attacker to intercept sensitive authentication codes over unencrypted connections.

CVSS v3
5.4
EG Score
5.4(medium)
EG Risk
24(Track)
EG Risk 24/100SSVC: Track

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
Severity54% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
8%
KEV
Not listed

Published

July 31, 2026

Last Modified

August 7, 2026

Advisory Details (2)

Auto-updated Jul 31, 2026
Patch available. Sources: redhat.
redhat

2508306 – (CVE-2026-18211) CVE-2026-18211 keycloak-services: keycloak-services: secure-client-uris policy bypass via localhost-prefixed domains

https://bugzilla.redhat.com/show_bug.cgi?id=2508306
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-18211

Vendor Advisories for CVE-2026-18211(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 21× in last 7d / 69× 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. 2026-08-21 02:35 UTCGHSA enrichment
  2. 2026-08-20 03:25 UTCEG score recompute
  3. 2026-08-20 03:25 UTCGHSA enrichment
  4. 2026-08-19 17:03 UTCEPSS rescore
  5. 2026-08-19 04:09 UTCEG score recompute
  6. 2026-08-19 04:09 UTCGHSA enrichment
  7. 2026-08-18 13:48 UTCEPSS rescore
  8. 2026-08-18 04:56 UTCEG score recompute
  9. 2026-08-18 04:56 UTCGHSA enrichment
  10. 2026-08-17 13:47 UTCEPSS rescore
  11. 2026-08-17 05:48 UTCEG score recompute
  12. 2026-08-17 05:48 UTCGHSA enrichment
  13. 2026-08-16 14:56 UTCEPSS rescore
  14. 2026-08-16 06:41 UTCEG score recompute
  15. 2026-08-16 06:41 UTCGHSA enrichment
  16. 2026-08-16 02:14 UTCEPSS rescore
  17. 2026-08-15 07:34 UTCEG score recompute
  18. 2026-08-15 07:34 UTCGHSA enrichment
  19. 2026-08-15 01:30 UTCEPSS rescore
  20. 2026-08-14 08:26 UTCEG score recompute
  21. 2026-08-14 08:26 UTCGHSA enrichment
  22. 2026-08-13 22:00 UTCEPSS rescore
  23. 2026-08-13 09:18 UTCEG score recompute
  24. 2026-08-13 09:18 UTCGHSA enrichment
  25. 2026-08-12 13:50 UTCEPSS rescore
Show 44 more
  1. 2026-08-12 10:11 UTCEG score recompute
  2. 2026-08-12 10:11 UTCGHSA enrichment
  3. 2026-08-11 13:42 UTCEPSS rescore
  4. 2026-08-11 11:02 UTCEG score recompute
  5. 2026-08-11 11:02 UTCGHSA enrichment
  6. 2026-08-11 00:00 UTCEPSS rescore
  7. 2026-08-10 11:54 UTCEG score recompute
  8. 2026-08-10 11:54 UTCGHSA enrichment
  9. 2026-08-09 13:46 UTCEPSS rescore
  10. 2026-08-09 12:47 UTCEG score recompute
  11. 2026-08-09 12:47 UTCGHSA enrichment
  12. 2026-08-08 16:37 UTCEPSS rescore
  13. 2026-08-08 13:39 UTCEG score recompute
  14. 2026-08-08 13:39 UTCGHSA enrichment
  15. 2026-08-07 14:31 UTCEG score recompute▲ 1.20
  16. 2026-08-07 14:31 UTCGHSA enrichment
  17. 2026-08-07 14:31 UTCNVD updateCVSS v3 → 5.4
  18. 2026-08-07 13:27 UTCGHSA enrichment
  19. 2026-08-06 14:20 UTCEG score recompute
  20. 2026-08-06 14:20 UTCGHSA enrichment
  21. 2026-08-06 13:46 UTCEPSS rescore
  22. 2026-08-05 19:17 UTCEPSS rescore
  23. 2026-08-05 15:12 UTCGHSA enrichment
  24. 2026-08-04 16:04 UTCEG score recompute
  25. 2026-08-04 16:04 UTCGHSA enrichment
  26. 2026-08-04 15:10 UTCEPSS rescore
  27. 2026-08-04 10:38 UTCEPSS rescore
  28. 2026-08-03 16:56 UTCGHSA enrichment
  29. 2026-08-03 13:52 UTCEG score recompute
  30. 2026-08-03 13:52 UTCGHSA enrichment
  31. 2026-08-03 10:35 UTCEPSS rescore
  32. 2026-08-02 14:45 UTCEG score recompute
  33. 2026-08-02 14:45 UTCGHSA enrichment
  34. 2026-08-02 02:26 UTCEPSS rescore
  35. 2026-08-01 15:37 UTCEG score recompute
  36. 2026-08-01 15:37 UTCGHSA enrichment
  37. 2026-08-01 04:15 UTCEPSS rescore
  38. 2026-07-31 16:29 UTCEG score recompute
  39. 2026-07-31 16:29 UTCGHSA enrichment
  40. 2026-07-31 15:34 UTCEG score recompute
  41. 2026-07-31 15:34 UTCGHSA enrichment
  42. 2026-07-31 08:18 UTCEG score recompute
  43. 2026-07-31 07:28 UTCEG score recompute
  44. 2026-07-31 07:28 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-18211?
CVE-2026-18211 is a medium vulnerability published on July 31, 2026. A flaw was found in the secure-client-uris client policy executor within Keycloak core services. This component is responsible for enforcing security requirements on client configurations, such as requiring encrypted connections for redirect URIs. Due to an improper check that only looks at the…
When was CVE-2026-18211 disclosed?
CVE-2026-18211 was first published in the National Vulnerability Database on July 31, 2026, with the most recent update on August 7, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18211 actively exploited?
CVE-2026-18211 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 92.3% of all scored CVEs.
What is the CVSS score of CVE-2026-18211?
CVE-2026-18211 has a CVSS v3 base score of 5.4 (NVD).
How do I remediate CVE-2026-18211?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18211, 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-2026-18211

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