CVE-2026-18211

MEDIUMNVD 5.45.4—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.4 under NVD CVSS v3. EPSS exploit probability: 0.3% (21st percentile of EPSS-scored CVEs). 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: 0.3%CVSS: 5.4Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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
5.4MEDIUMmedium confidence
EG Risk
24
EG Risk 24/100CISA 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
Severity54% × 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
0.3%
EPSS %ILE
21st
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

July 31, 2026

Last Modified

August 31, 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 13× in last 7d / 61× 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.

Showing the most recent 100 of 166 total refreshes for this CVE.

  1. 2026-10-04 23:21 UTCEPSS rescore
  2. 2026-10-04 06:33 UTCEG score recompute
  3. 2026-10-04 06:33 UTCGHSA enrichment
  4. 2026-10-03 14:25 UTCEPSS rescore
  5. 2026-10-02 16:51 UTCEG score recompute
  6. 2026-10-02 16:51 UTCGHSA enrichment
  7. 2026-10-01 19:49 UTCEPSS rescore
  8. 2026-10-01 02:48 UTCEG score recompute
  9. 2026-10-01 02:48 UTCGHSA enrichment
  10. 2026-09-30 15:02 UTCEPSS rescore
  11. 2026-09-29 15:20 UTCEPSS rescore
  12. 2026-09-29 06:50 UTCEG score recompute
  13. 2026-09-29 06:50 UTCGHSA enrichment
  14. 2026-09-28 13:51 UTCEPSS rescore
  15. 2026-09-27 18:57 UTCEG score recompute
  16. 2026-09-27 18:57 UTCGHSA enrichment
  17. 2026-09-27 13:47 UTCEPSS rescore
  18. 2026-09-26 15:58 UTCEPSS rescore
  19. 2026-09-25 04:53 UTCEG score recompute
  20. 2026-09-25 04:53 UTCGHSA enrichment
  21. 2026-09-23 16:48 UTCEG score recompute
  22. 2026-09-23 16:48 UTCGHSA enrichment
  23. 2026-09-22 13:23 UTCEG score recompute
  24. 2026-09-22 13:23 UTCGHSA enrichment
  25. 2026-09-20 03:40 UTCEG score recompute
Show 75 more
  1. 2026-09-20 03:40 UTCGHSA enrichment
  2. 2026-09-19 04:06 UTCEG score recompute
  3. 2026-09-19 04:06 UTCGHSA enrichment
  4. 2026-09-18 19:27 UTCEPSS rescore
  5. 2026-09-18 03:45 UTCEG score recompute
  6. 2026-09-18 03:45 UTCGHSA enrichment
  7. 2026-09-17 04:37 UTCEG score recompute
  8. 2026-09-17 04:37 UTCGHSA enrichment
  9. 2026-09-16 14:07 UTCEPSS rescore
  10. 2026-09-16 05:29 UTCEG score recompute
  11. 2026-09-16 05:29 UTCGHSA enrichment
  12. 2026-09-16 05:14 UTCEPSS rescore
  13. 2026-09-15 03:04 UTCGHSA enrichment
  14. 2026-09-14 03:30 UTCEG score recompute
  15. 2026-09-14 03:30 UTCGHSA enrichment
  16. 2026-09-13 16:46 UTCEPSS rescore
  17. 2026-09-13 04:22 UTCEG score recompute
  18. 2026-09-13 04:22 UTCGHSA enrichment
  19. 2026-09-12 15:00 UTCEPSS rescore
  20. 2026-09-12 05:14 UTCEG score recompute
  21. 2026-09-12 05:14 UTCGHSA enrichment
  22. 2026-09-11 14:52 UTCEPSS rescore
  23. 2026-09-11 09:36 UTCEPSS rescore
  24. 2026-09-11 06:06 UTCEG score recompute
  25. 2026-09-11 06:06 UTCGHSA enrichment
  26. 2026-09-10 09:34 UTCEPSS rescore
  27. 2026-09-10 06:57 UTCGHSA enrichment
  28. 2026-09-09 07:06 UTCEG score recompute
  29. 2026-09-09 07:06 UTCGHSA enrichment
  30. 2026-09-08 22:00 UTCEPSS rescore
  31. 2026-09-07 19:37 UTCEG score recompute
  32. 2026-09-07 19:37 UTCGHSA enrichment
  33. 2026-09-07 16:01 UTCEPSS rescore
  34. 2026-09-06 13:47 UTCEPSS rescore
  35. 2026-09-06 09:43 UTCEG score recompute
  36. 2026-09-06 09:43 UTCGHSA enrichment
  37. 2026-09-05 10:34 UTCEG score recompute
  38. 2026-09-05 10:34 UTCGHSA enrichment
  39. 2026-09-04 11:21 UTCEG score recompute
  40. 2026-09-04 11:21 UTCGHSA enrichment
  41. 2026-09-04 05:06 UTCEPSS rescore
  42. 2026-09-03 09:13 UTCEG score recompute
  43. 2026-09-03 09:13 UTCGHSA enrichment
  44. 2026-09-02 14:11 UTCEPSS rescore
  45. 2026-09-01 22:34 UTCEG score recompute
  46. 2026-09-01 22:34 UTCGHSA enrichment
  47. 2026-09-01 13:53 UTCEPSS rescore
  48. 2026-09-01 04:39 UTCEPSS rescore
  49. 2026-08-31 15:39 UTCGHSA enrichment
  50. 2026-08-30 21:31 UTCEG score recompute
  51. 2026-08-30 21:31 UTCGHSA enrichment
  52. 2026-08-30 19:17 UTCEPSS rescore
  53. 2026-08-30 01:22 UTCEPSS rescore
  54. 2026-08-29 22:23 UTCEG score recompute
  55. 2026-08-29 22:23 UTCGHSA enrichment
  56. 2026-08-28 21:41 UTCEPSS rescore
  57. 2026-08-27 20:46 UTCEG score recompute
  58. 2026-08-27 20:46 UTCGHSA enrichment
  59. 2026-08-27 14:25 UTCEPSS rescore
  60. 2026-08-26 21:22 UTCEG score recompute
  61. 2026-08-26 21:22 UTCGHSA enrichment
  62. 2026-08-26 14:46 UTCEPSS rescore
  63. 2026-08-25 22:15 UTCGHSA enrichment
  64. 2026-08-24 23:06 UTCEG score recompute
  65. 2026-08-24 23:06 UTCGHSA enrichment
  66. 2026-08-23 23:58 UTCGHSA enrichment
  67. 2026-08-23 00:51 UTCEG score recompute
  68. 2026-08-23 00:51 UTCGHSA enrichment
  69. 2026-08-23 00:19 UTCEPSS rescore
  70. 2026-08-22 01:43 UTCEG score recompute
  71. 2026-08-22 01:43 UTCGHSA enrichment
  72. 2026-08-21 23:49 UTCEPSS rescore
  73. 2026-08-21 02:35 UTCGHSA enrichment
  74. 2026-08-20 03:25 UTCEG score recompute
  75. 2026-08-20 03:25 UTCGHSA enrichment

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 on July 31, 2026, with the most recent update on August 31, 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 0.3% probability of exploitation in the next 30 days (21st percentile of EPSS-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?
A fix for CVE-2026-18211 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-18211 are linked in the Vendor Advisories panel on this page.

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