CVE-2026-16093 (GCVE-0-2026-16093)
Vulnerability from cvelistv5 – Published: 2026-07-17 16:42 – Updated: 2026-07-21 01:45
VLAI
EPSS
VEX
Title
Keycloak-services: keycloak-services: required signed-jwt assertion policy can be bypassed with unsigned assertion headers
Summary
Keycloak provides a mechanism called Client Policies to enforce security requirements on clients, such as requiring them to use signed JWTs for authentication. A flaw was discovered where this enforcement can be bypassed. An attacker with valid client credentials can provide a fake, unsigned assertion header that tricks the system into thinking the policy requirements have been met. This allows the attacker to authenticate using simpler methods like a client secret even when the administrator has mandated more secure, signed assertions.
Severity
5.4 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-807 - Reliance on Untrusted Inputs in a Security Decision
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://access.redhat.com/security/cve/CVE-2026-16093 | vdb-entryx_refsource_REDHAT |
| https://bugzilla.redhat.com/show_bug.cgi?id=2501729 | issue-trackingx_refsource_REDHAT |
Impacted products
4 products
| Vendor | Product | Version | |
|---|---|---|---|
| Red Hat | Red Hat Build of Keycloak |
cpe:/a:redhat:build_keycloak: |
|
| Red Hat | Red Hat Data Grid 8 |
cpe:/a:redhat:jboss_data_grid:8 |
|
| Red Hat | Red Hat JBoss Enterprise Application Platform Expansion Pack |
cpe:/a:redhat:jbosseapxp |
|
| Red Hat | Red Hat Single Sign-On 7 |
cpe:/a:redhat:red_hat_single_sign_on:7 |
Date Public
2026-07-16 17:01
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
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