How severe is CVE-2026-27478?

CVE-2026-27478 has a CVSS score of 9.1/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-27478?

CVE-2026-27478 affects the following packages: io.unitycatalog:unitycatalog-server (Maven). Ecosystems affected: Maven.

How do I fix CVE-2026-27478?

Update io.unitycatalog:unitycatalog-server to 0.4.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-27478 is resolved across your whole dependency graph.

How do I detect CVE-2026-27478 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.unitycatalog:unitycatalog-server. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-27478 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-27478?

O3 pinpoints whether CVE-2026-27478 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-27478 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-27478 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was CVE-2026-27478 published, and has it been updated?

CVE-2026-27478 was published on March 11, 2026 and was last updated on August 7, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

CRITICAL severity

CVE-2026-27478

CRITICAL

CVE-2026-27478 is a critical-severity (CVSS 9.1) vulnerability in io.unitycatalog:unitycatalog-server. O3 Security confirms whether CVE-2026-27478 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Unity Catalog has a JWT Issuer Validation Bypass Allows Complete User Impersonation

Also known asGHSA-qqcj-rghw-829x

Published

Mar 11, 2026

Updated

Aug 7, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Aug 7, 2026 · OSV.dev, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

☕io.unitycatalog:unitycatalog-server

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

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.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`io.unitycatalog:unitycatalog-server`	all versions	0.4.1

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.unitycatalog:unitycatalog-server. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update io.unitycatalog:unitycatalog-server to 0.4.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-27478 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-27478 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-27478. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2026-27478 in your dependencies?

O3 detects CVE-2026-27478 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works