8.1

CVE-2026-11800: redhat build_of_keycloak

CVSS: 8.1v3.1HighAnalyzed
Published 25-06-2026Last modified 15-07-2026
Open JSON

Vulnerability summary

CVE-2026-11800 is a high (CVSS 8.1) vulnerability in redhat build_of_keycloak. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 21.3% of scored vulnerabilities.

Overall risk
32/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.1/10
010
High · v3.1 (CVE.org)
EPSS score
0.30%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 25-06-2026
    PublishedVulnerability first disclosed.
  2. 15-07-2026
    Last modifiedVulnerability information updated.

Description

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 metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.30%

Chance of exploitation in the next 30 days

Percentile

21%

Versus all other CVEs

30-day change

0.00 pp

From 0.30% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.30%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Redhat1 product

1 vendor · 1 product

References

5 links