CVE-2026-18208

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 6.5 from GitHub Security Advisory published 2026-07-31. The CNA's CVSS baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: the CNA's CVSS, EPSS, GitHub Security Advisory

Also known asEUVD-2026-51482 (ENISA EUVD) · GHSA-jg59-c35g-76r8 (GitHub Security Advisories)Source: ENISA EUVD

6.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.5Exploit: None knownExposed services: Not assessed

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

A flaw was found in the OIDC token introspection endpoint of the keycloak-services component. Keycloak is an open-source identity and access management solution used to secure modern applications and services. The issue occurs when a confidential client, configured to receive signed JWT introspection responses, attempts to introspect a token issued for a different audience. Although the endpoint correctly identifies the token as inactive for that client, it still returns the full set of token claims within a signed JWT field. This allows an unauthorized client to bypass audience-based restrictions and access sensitive information contained in the token.

CVSS v3
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
29
EG Risk 29/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity65% × 45%
Impact severity (EG Severity): CVSS 6.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.3% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.3%
EPSS %ILE
27th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (6.5): severity, escalated by confirmed exploitation. This CVE's 6.5 is its impact severity (EG Severity), not escalated.

EG Severity
6.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

July 31, 2026

Last Modified

August 31, 2026

Advisory Details (2)

Auto-updated Jul 31, 2026
No fix on record yet. Sources: redhat.
Red Hat

2508304 – (CVE-2026-18208) CVE-2026-18208 keycloak-services: keycloak-services: Inactive out-of-audience token introspection leaks signed JWT claim

https://bugzilla.redhat.com/show_bug.cgi?id=2508304
Red HatMentions a patch (unverified)

cve-details

https://access.redhat.com/security/cve/CVE-2026-18208

Vendor Advisories for CVE-2026-18208(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 8× in last 7d / 46× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 196 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 96 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  2. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  3. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  4. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  5. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  6. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  7. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.3% · 27th percentile
  8. 2026-10-25 14:45 UTCEG score recompute
  9. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  10. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  11. 2026-10-23 06:00 UTCEG score recompute
  12. 2026-10-23 06:00 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  13. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  14. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  15. 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  16. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  17. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  18. 2026-10-18 03:59 UTCEG score recompute
  19. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  20. 2026-10-16 16:40 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  21. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  22. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  23. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  24. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  25. 2026-10-12 16:27 UTCEG score recompute
Show 75 more
  1. 2026-10-11 20:07 UTCEG score recompute
  2. 2026-10-11 17:20 UTCEG score recompute
  3. 2026-10-11 14:52 UTCEG score recompute
  4. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  5. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  6. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  7. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  8. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  9. 2026-10-06 23:51 UTCEG score recompute
  10. 2026-10-06 23:51 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  11. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  12. 2026-10-05 19:57 UTCEG score recompute
  13. 2026-10-05 19:56 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  14. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  15. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  16. 2026-10-04 06:33 UTCEG score recompute
  17. 2026-10-04 06:33 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  18. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  19. 2026-10-02 16:52 UTCEG score recompute
  20. 2026-10-02 16:52 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  21. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  22. 2026-10-01 02:48 UTCEG score recompute
  23. 2026-10-01 02:48 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  24. 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  25. 2026-09-29 15:20 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  26. 2026-09-29 06:50 UTCEG score recompute
  27. 2026-09-29 06:50 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  28. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  29. 2026-09-27 18:57 UTCEG score recompute
  30. 2026-09-27 18:57 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  31. 2026-09-27 13:47 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  32. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  33. 2026-09-25 04:53 UTCEG score recompute
  34. 2026-09-25 04:53 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  35. 2026-09-23 16:48 UTCEG score recompute
  36. 2026-09-23 16:48 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  37. 2026-09-22 13:23 UTCEG score recompute
  38. 2026-09-22 13:23 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  39. 2026-09-19 23:43 UTCEG score recompute
  40. 2026-09-19 23:43 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  41. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  42. 2026-09-18 10:44 UTCEG score recompute
  43. 2026-09-18 10:44 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  44. 2026-09-17 08:17 UTCEG score recompute
  45. 2026-09-17 08:17 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  46. 2026-09-16 14:07 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  47. 2026-09-16 05:29 UTCEG score recompute
  48. 2026-09-16 05:29 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  49. 2026-09-16 05:14 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  50. 2026-09-15 03:04 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  51. 2026-09-13 19:47 UTCEG score recompute
  52. 2026-09-13 19:47 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  53. 2026-09-13 16:46 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  54. 2026-09-12 17:23 UTCEG score recompute
  55. 2026-09-12 17:23 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  56. 2026-09-12 15:00 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  57. 2026-09-11 14:58 UTCEG score recompute
  58. 2026-09-11 14:58 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  59. 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  60. 2026-09-11 09:36 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  61. 2026-09-10 10:02 UTCEG score recompute
  62. 2026-09-10 10:02 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  63. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  64. 2026-09-09 07:07 UTCEG score recompute
  65. 2026-09-09 07:06 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  66. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  67. 2026-09-07 23:43 UTCEG score recompute
  68. 2026-09-07 23:42 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  69. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  70. 2026-09-06 21:18 UTCEG score recompute
  71. 2026-09-06 21:18 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  72. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  73. 2026-09-05 18:47 UTCEG score recompute
  74. 2026-09-05 18:47 UTCGHSA enrichmentGHSA-jg59-c35g-76r8 · GitHub CVSS 6.5
  75. 2026-09-04 11:38 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-18208?
CVE-2026-18208 is a medium-severity vulnerability; its CVE record was published on July 31, 2026. A flaw was found in the OIDC token introspection endpoint of the keycloak-services component. Keycloak is an open-source identity and access management solution used to secure modern applications and services. The issue occurs when a confidential client, configured to receive signed JWT…
When was CVE-2026-18208 made public?
CVE-2026-18208 was made public on July 28, 2026: that is the date its CVE record's CNA, Red Hat, Inc., gives for when the vulnerability was made public. The CVE record itself was published on July 31, 2026. EchelonGraph's copy of the record carries a last-modified date of August 31, 2026; the record at its source may have been updated since.
Is CVE-2026-18208 actively exploited?
CVE-2026-18208 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (27th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-18208?
CVE-2026-18208 has a CVSS base score of 6.5 (the CNA's own assessment, by redhat; NVD's own analysis pending).
How do I remediate CVE-2026-18208?
No fix for CVE-2026-18208 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-18208 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-18208

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