Vulnerability GHSA-j97h-3f8r-mrjr
High Risk
HIGH RISK
CVSS Score: 8.1
Score Range: 7.0–8.9
High severity vulnerabilities (CVSS 7.0–8.9). Serious vulnerabilities that should be prioritized soon after critical fixes.
17 hours ago
November 03, 2026 at 05:24 PM UTC
Keycloak has authentication bypass via jwt algorithm confusion
1.0-alpha-1 and 1.0-alpha-1-12062013 - 1.0-beta-1 and 1.0-beta-1-20150521 and 1.0-beta-1-20150523 - 1.5.0-Final and 1.5.0.Final - 26.6.3
1.0-alpha-1 and 1.0-alpha-1-12062013 - 1.0-beta-1 and 1.0-beta-1-20150521 and 1.0-beta-1-20150523 - 1.5.0-Final and 1.5.0.Final - 26.6.3
Summary
Keycloak has authentication bypass via jwt algorithm confusion
Details
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.
Related Vulnerabilities
Other vulnerabilities affecting the same packages
High Risk
5 days ago
Keycloak vulnerable to cross-site scripting (xss) via case-insensitive uri validation bypass
1.0-alpha-1 and 1.0-alpha-1-12062013 - 1.0-beta-1 and 1.0-beta-1-20150521 and 1.0-beta-1-20150523 - 1.5.0-Final and 1.5.0.Final - 26.6.3 GHSA-v3f7-2p4r-mwfw
1.0-alpha-1 and 1.0-alpha-1-12062013 - 1.0-beta-1 and 1.0-beta-1-20150521 and 1.0-beta-1-20150523 - 1.5.0-Final and 1.5.0.Final - 26.6.3 GHSA-v3f7-2p4r-mwfw
Medium Risk
5 days ago
Keycloak vulnerable to information disclosure through arbitrary filesystem path probing
1.0-alpha-1 and 1.0-alpha-1-12062013 - 1.0-beta-1 and 1.0-beta-1-20150521 and 1.0-beta-1-20150523 - 1.5.0-Final and 1.5.0.Final - 26.6.3 GHSA-9jrw-8xf7-xqhq
1.0-alpha-1 and 1.0-alpha-1-12062013 - 1.0-beta-1 and 1.0-beta-1-20150521 and 1.0-beta-1-20150523 - 1.5.0-Final and 1.5.0.Final - 26.6.3 GHSA-9jrw-8xf7-xqhq
Medium Risk
5 days ago
Keycloak allows unauthorized access to resources via uma permission ticket bypass
1.0-alpha-1 and 1.0-alpha-1-12062013 - 1.0-beta-1 and 1.0-beta-1-20150521 and 1.0-beta-1-20150523 - 1.5.0-Final and 1.5.0.Final - 26.6.3 GHSA-w3p3-7cjg-vgfw
1.0-alpha-1 and 1.0-alpha-1-12062013 - 1.0-beta-1 and 1.0-beta-1-20150521 and 1.0-beta-1-20150523 - 1.5.0-Final and 1.5.0.Final - 26.6.3 GHSA-w3p3-7cjg-vgfw
High Risk
5 days ago
Keycloak vulnerable to authorization bypass via incorrect uri comparison
1.0-alpha-1 and 1.0-alpha-1-12062013 - 1.0-beta-1 and 1.0-beta-1-20150521 and 1.0-beta-1-20150523 - 1.5.0-Final and 1.5.0.Final - 26.6.3 GHSA-f5p5-6xmx-p252
1.0-alpha-1 and 1.0-alpha-1-12062013 - 1.0-beta-1 and 1.0-beta-1-20150521 and 1.0-beta-1-20150523 - 1.5.0-Final and 1.5.0.Final - 26.6.3 GHSA-f5p5-6xmx-p252
Medium Risk
5 days ago
Keycloak: Attacker can re-enable and take over disabled clients via registration access token
1.0-alpha-1 and 1.0-alpha-1-12062013 - 1.0-beta-1 and 1.0-beta-1-20150521 and 1.0-beta-1-20150523 - 1.5.0-Final and 1.5.0.Final - 26.6.3 GHSA-r7rc-c989-86g6
1.0-alpha-1 and 1.0-alpha-1-12062013 - 1.0-beta-1 and 1.0-beta-1-20150521 and 1.0-beta-1-20150523 - 1.5.0-Final and 1.5.0.Final - 26.6.3 GHSA-r7rc-c989-86g6
Impacted packages
Timeline
Published
17 hours ago
November 03, 2026 at 05:24 PM UTC
Fixed (26.6.4)
Unknown
Unknown
Last Modified
16 hours ago
November 03, 2026 at 05:55 PM UTC