CVE-2026-27478 Unity Catalog has a JWT Issuer Validation Bypass Allows Complete User Impersonation
Attackers can impersonate any user by bypassing JWT issuer validation in Unity Catalog's token exchange endpoint, leading to complete account takeover.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-27478?
CVE-2026-27478 is a critical authentication bypass vulnerability in unitycatalog, published on 11 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Unity Catalog is an open, multi-modal Catalog for data and AI. In 0.4.0 and earlier, a critical authentication bypass vulnerability exists in the Unity Catalog token exchange endpoint (/api/1.0/unity-control/auth/tokens). The endpoint extracts the issuer (iss) claim from incoming JWTs and uses it to dynamically fetch the JWKS endpoint for signature validation without validating that the issuer is a trusted identity provider.
Which versions are affected by CVE-2026-27478?
2 open source packages ship an affected version, including io.unitycatalog:unitycatalog-server. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
io.unitycatalog:unitycatalog-server Maven | All versions | 0.4.1 |
io.unitycatalog:unitycatalog-server Maven | All versions | 0.4.1 |
Products include Unitycatalog Unitycatalog.
How do I fix CVE-2026-27478?
Upgrade io.unitycatalog:unitycatalog-server to 0.4.1 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-27478 being exploited?
There is no known exploitation of CVE-2026-27478 in the wild and no public exploit code.
Sources
Also known as GHSA-qqcj-rghw-829x.