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High 8.1Published Jun 25, 2026

CVE-2026-11800A flaw was found in Keycloak.

Updated under an hour ago ()

Does this affect you?

It affects redhat build_of_keycloak. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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
8.1 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weakness (CWE)
CWE-347
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
Not given
NVD analysis
Analyzed
Record last updated
Jul 15, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
redhat build_of_keycloak
redhat:build_of_keycloak
from 26.6 before 26.6.4
NVD

References

  • vendor-advisory
  • vendor-advisory
  • vendor-advisory
  • vendor-advisory
  • vendor-advisory

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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