Vulnerability-Lookup

GHSA-JMHG-9C54-P575

Vulnerability from github – Published: 2026-07-17 18:31 – Updated: 2026-07-17 18:31

Details

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)


                  
                    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

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  "affected": [],
  "aliases": [
    "CVE-2026-16093"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-807"
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    "github_reviewed": false,
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  "id": "GHSA-jmhg-9c54-p575",
  "modified": "2026-07-17T18:31:26Z",
  "published": "2026-07-17T18:31:26Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-16093"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2026-16093"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2501729"
    }
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  "schema_version": "1.4.0",
  "severity": [
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      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-16093 (GCVE-0-2026-16093)

Vulnerability from cvelistv5 – Published: 2026-07-17 16:42 – Updated: 2026-07-21 01:45

Title

Keycloak-services: keycloak-services: required signed-jwt assertion policy can be bypassed with unsigned assertion headers

Summary

Severity

5.4 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

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

redhat

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

Credits

Red Hat would like to thank Paul Bottinelli (Trail of Bits) for reporting this issue.

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JSON

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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.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-JMHG-9C54-P575

CVE-2026-16093 (GCVE-0-2026-16093)

Tags

Sightings

Nomenclature