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Keycloak: Unauthorized access via improper validation of encrypted SAML assertions

High severity GitHub Reviewed Published Mar 18, 2026 to the GitHub Advisory Database • Updated Apr 15, 2026

Package

maven org.keycloak:keycloak-saml-adapter-core (Maven)

Affected versions

< 26.2.14
>= 26.3.0, < 26.4.10
>= 26.5.0, < 26.5.5

Patched versions

26.2.14
26.4.10
26.5.5
maven org.keycloak:keycloak-saml-core (Maven)
>= 26.3.0, < 26.4.10
< 26.2.14
>= 26.5.0, < 26.5.5
26.4.10
26.2.14
26.5.5
maven org.keycloak:keycloak-services (Maven)
>= 26.5.0, < 26.5.5
< 26.2.14
>= 26.3.0, < 26.4.10
26.5.5
26.2.14
26.4.10

Description

A flaw was found in Keycloak. Keycloak's Security Assertion Markup Language (SAML) broker endpoint does not properly validate encrypted assertions when the overall SAML response is not signed. An attacker with a valid signed SAML assertion can exploit this by crafting a malicious SAML response. This allows the attacker to inject an encrypted assertion for an arbitrary principal, leading to unauthorized access and potential information disclosure.

References

Published by the National Vulnerability Database Mar 18, 2026
Published to the GitHub Advisory Database Mar 18, 2026
Reviewed Mar 18, 2026
Last updated Apr 15, 2026

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
Low
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(28th percentile)

Weaknesses

Improper Validation of Specified Type of Input

The product receives input that is expected to be of a certain type, but it does not validate or incorrectly validates that the input is actually of the expected type. Learn more on MITRE.

CVE ID

CVE-2026-2092

GHSA ID

GHSA-wmxr-6j5f-838p

Source code

Credits

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