Unauthenticated user impersonation via untrusted JWT issuer
Published Mar 11, 2026 · Updated Mar 11, 2026
Authentication bypass in Unity Catalog 0.4.0 and earlier allows remote attackers to impersonate any known user through token exchange. The token endpoint trusts the JWT iss claim to discover and fetch the signer's JWKS, then accepts its signature without allowlisting the issuer or validating aud. No credentials or user interaction are required, but authorization must be enabled and attackers must know a target user identity; the resulting token inherits that user's permissions.
Summary
What happened
Authentication bypass in Unity Catalog 0.4.0 and earlier allows remote attackers to impersonate any known user through token exchange. The token endpoint trusts the JWT iss claim to discover and fetch the signer's JWKS, then accepts its signature without allowlisting the issuer or validating aud. No credentials or user interaction are required, but authorization must be enabled and attackers must know a target user identity; the resulting token inherits that user's permissions.
The record
- CVE
- CVE-2026-27478
- Published
- Mar 11, 2026
- Updated
- Mar 11, 2026
- Vendor
- Unity Catalog
- Product
- Unity Catalog
- Classifications
- CWE-1390, CWE-290, CWE-346, T1606
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 11, 2026CVE publishedPublication date reported by the CVE source.
- Mar 11, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=<= 0.4.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Unity Catalog token-exchange proof of conceptproof of concept · unverified
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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