CVE-2026-11800

HIGHPre-NVD 8.18.1
EchelonGraph scoreHIGH confidence

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

Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2026-11-03. A secondary CVSS source baseline 8.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source

Also known asEUVD-2026-39567 (ENISA EUVD) · GHSA-gqj5-2xp5-3qmp (GitHub Security Advisories) · GHSA-j97h-3f8r-mrjr (GitHub Security Advisories)Source: ENISA EUVD

8.1EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 8.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

A flaw was found in Keycloak. This JWT algorithm confusion vulnerability in the JWT Authorization Grant flow allows an attacker with valid client credentials to bypass signature verification. By forging an assertion, the attacker can create unauthorized access tokens. This enables the attacker to impersonate any federated user linked to the affected Identity Provider, leading to unauthorized access and potential privilege escalation.

CVSS v3
8.1
EG Score
8.1HIGHhigh confidence
EG Risk
37
EG Risk 37/100

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)
Severity81% × 45%
Impact severity (EG Severity): CVSS 8.1 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 low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.3%
EPSS %ILE
18th
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 (8.1): severity, escalated by confirmed exploitation. This CVE's 8.1 is its impact severity (EG Severity), not escalated.

EG Severity
8.1 HIGHCVSS-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. 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 low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

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

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (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

June 25, 2026

Last Modified

October 25, 2026

Advisory Details (4)

Auto-updated Jun 25, 2026
Patch available. Sources: redhat.
Red Hat

2487006 – (CVE-2026-11800) CVE-2026-11800 org.keycloak:keycloak-services: Keycloak: Authentication bypass via JWT algorithm confusion

https://bugzilla.redhat.com/show_bug.cgi?id=2487006
Red HatMentions a patch (unverified)

cve-details

https://access.redhat.com/security/cve/CVE-2026-11800
Red HatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:30084
Red HatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:30083

Patch Availability(3)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatpatch2026-06-25redhat
redhatrhbk/keycloak-rhel9-operator:26.6-82026-06-25redhat
mavenorg.keycloak:keycloak-services @ 26.6.4 (fixes < 26.6.4)—ghsa

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.

Affected Packages

(1 across 1 ecosystem)
Maven(1)
PackageVulnerable rangeFix by version rangeDependents
org.keycloak:keycloak-services1.0-alpha-1 ... 9.0.3 (228 versions)
  • every version up to 26.6.4: fixed in 26.6.4
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 40× 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 its CVE.org record (CNA or CISA ADP). 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 398 rows 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 298 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:50 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  2. 2026-11-12 16:33 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  3. 2026-11-11 16:38 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  4. 2026-11-10 16:42 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  5. 2026-11-09 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  6. 2026-11-08 16:38 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  7. 2026-11-08 08:51 UTCEchelonGraph re-scored
  8. 2026-11-08 08:51 UTCVendor advisory
  9. 2026-11-08 08:51 UTCGHSA enrichmentGHSA-j97h-3f8r-mrjr · GitHub severity HIGH · GitHub CVSS 8.1
  10. 2026-11-07 16:38 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  11. 2026-11-06 16:36 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  12. 2026-11-05 16:36 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  13. 2026-11-04 16:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  14. 2026-11-03 16:46 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  15. 2026-11-02 16:44 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  16. 2026-11-02 08:19 UTCEchelonGraph re-scored
  17. 2026-11-02 08:19 UTCVendor advisory
  18. 2026-11-02 08:19 UTCGHSA enrichmentGHSA-gqj5-2xp5-3qmp · GitHub severity HIGH · GitHub CVSS 8.1
  19. 2026-11-01 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  20. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  21. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  22. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  23. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  24. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  25. 2026-10-26 16:30 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
Show 75 more
  1. 2026-10-25 22:27 UTCEchelonGraph re-scored
  2. 2026-10-25 22:27 UTCVendor advisory
  3. 2026-10-25 22:27 UTCGHSA enrichmentGHSA-gqj5-2xp5-3qmp · GitHub severity HIGH · GitHub CVSS 8.1
  4. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  5. 2026-10-25 14:50 UTCEchelonGraph re-scored
  6. 2026-10-25 04:54 UTCEchelonGraph re-scored
  7. 2026-10-25 04:54 UTCVendor advisory
  8. 2026-10-25 04:54 UTCGHSA enrichmentGHSA-gqj5-2xp5-3qmp · GitHub severity HIGH · GitHub CVSS 8.1
  9. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  10. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  11. 2026-10-22 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  12. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  13. 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  14. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  15. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  16. 2026-10-18 05:04 UTCEchelonGraph re-scored
  17. 2026-10-17 19:01 UTCEchelonGraph re-scored
  18. 2026-10-17 19:01 UTCVendor advisory
  19. 2026-10-17 19:01 UTCGHSA enrichmentGHSA-gqj5-2xp5-3qmp · GitHub severity HIGH · GitHub CVSS 8.1
  20. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  21. 2026-10-16 16:40 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  22. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  23. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  24. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  25. 2026-10-12 16:37 UTCEchelonGraph re-scored
  26. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  27. 2026-10-11 20:13 UTCEchelonGraph re-scored
  28. 2026-10-11 18:25 UTCEchelonGraph re-scored
  29. 2026-10-11 14:58 UTCEchelonGraph re-scored
  30. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  31. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  32. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  33. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  34. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  35. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  36. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  37. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  38. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  39. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  40. 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  41. 2026-09-29 15:20 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  42. 2026-09-28 13:50 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  43. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.3% · 20th percentile
  44. 2026-09-23 13:47 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  45. 2026-09-23 08:24 UTCEchelonGraph re-scored
  46. 2026-09-23 08:24 UTCVendor advisory
  47. 2026-09-23 08:24 UTCGHSA enrichmentGHSA-gqj5-2xp5-3qmp · GitHub severity HIGH · GitHub CVSS 8.1
  48. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  49. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  50. 2026-09-18 07:19 UTCEchelonGraph re-scored
  51. 2026-09-18 07:19 UTCVendor advisory
  52. 2026-09-18 07:19 UTCGHSA enrichmentGHSA-gqj5-2xp5-3qmp · GitHub severity HIGH · GitHub CVSS 8.1
  53. 2026-09-16 05:14 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  54. 2026-09-14 01:16 UTCEchelonGraph re-scored
  55. 2026-09-14 01:16 UTCVendor advisory
  56. 2026-09-14 01:16 UTCGHSA enrichmentGHSA-gqj5-2xp5-3qmp · GitHub severity HIGH · GitHub CVSS 8.1
  57. 2026-09-13 16:46 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  58. 2026-09-13 09:37 UTCVendor advisory
  59. 2026-09-13 09:37 UTCGHSA enrichmentGHSA-gqj5-2xp5-3qmp · GitHub severity HIGH · GitHub CVSS 8.1
  60. 2026-09-12 15:41 UTCEchelonGraph re-scored
  61. 2026-09-12 15:41 UTCVendor advisory
  62. 2026-09-12 15:41 UTCGHSA enrichmentGHSA-gqj5-2xp5-3qmp · GitHub severity HIGH · GitHub CVSS 8.1
  63. 2026-09-12 15:00 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  64. 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  65. 2026-09-11 09:36 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  66. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  67. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  68. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  69. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  70. 2026-09-02 14:11 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  71. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  72. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  73. 2026-08-30 19:28 UTCEchelonGraph re-scored
  74. 2026-08-30 19:28 UTCVendor advisory
  75. 2026-08-30 19:28 UTCGHSA enrichmentGHSA-gqj5-2xp5-3qmp · GitHub severity HIGH · GitHub CVSS 8.1

Frequently asked(5)

What is CVE-2026-11800?
CVE-2026-11800 is a high-severity vulnerability; its CVE record was published on June 25, 2026. A flaw was found in Keycloak. This JWT algorithm confusion vulnerability in the JWT Authorization Grant flow allows an attacker with valid client credentials to bypass signature verification. By forging an assertion, the attacker can create unauthorized access tokens. This enables the attacker to…
When was CVE-2026-11800 made public?
CVE-2026-11800 was made public on May 29, 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 June 25, 2026. EchelonGraph's copy of the record carries a last-modified date of October 25, 2026; the record at its source may have been updated since.
Is CVE-2026-11800 actively exploited?
CVE-2026-11800 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (18th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-11800?
CVE-2026-11800 has a CVSS base score of 8.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-11800?
A fix for CVE-2026-11800 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-11800 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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