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.
CVE-2026-16093
MEDIUMPre-NVD 5.45.4—Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
Score 5.4 from GitHub Security Advisory published 2026-07-17. a secondary CVSS source baseline 5.4; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: ghsa, secondary
5.4
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.4Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.4
- EG Score
- 5.4(high)
- EPSS
- 9.3%
- KEV
- Not listed
Published
July 17, 2026
Last Modified
July 21, 2026
Advisory Details (2)
Auto-updated Jul 17, 2026Patch available. Sources: redhat.
redhat
2501729 – (CVE-2026-16093) CVE-2026-16093 keycloak-services: keycloak-services: Required signed-JWT assertion policy can be bypassed with unsigned assertion headers
https://bugzilla.redhat.com/show_bug.cgi?id=2501729Vendor Advisories for CVE-2026-16093(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 10× in last 7d / 10× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:24 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:30 UTCEPSS rescore
- 2026-07-19 02:28 UTCEPSS rescore
- 2026-07-17 20:02 UTCEG score recompute
- 2026-07-17 20:02 UTCGHSA enrichment
- 2026-07-17 18:02 UTCEG score recompute
- 2026-07-17 16:46 UTCEG score recompute
- 2026-07-17 16:44 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-16093?
CVE-2026-16093 is a medium vulnerability published on July 17, 2026. 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…
When was CVE-2026-16093 disclosed?
CVE-2026-16093 was first published in the National Vulnerability Database on July 17, 2026, with the most recent update on July 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-16093 actively exploited?
CVE-2026-16093 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 9.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-16093?
CVE-2026-16093 has a CVSS v3 base score of 5.4 (NVD).
How do I remediate CVE-2026-16093?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-16093, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-16093
Is Your Infrastructure Affected by CVE-2026-16093?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.