# CVE-2026-125370: Kubero 3.0.0 through 3.1.1 Authentication Bypass via Hardcoded JWT Secret


- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 9 Nov 2026
- **Updated:** 11 Nov 2026
- **Also known as:** GHSA-42fc-m93g-j65w

## What is CVE-2026-125370?

CVE-2026-125370 is a critical vulnerability in kubero-dev kubero, published on 9 Nov 2026. 

### Official description

Kubero 3.0.0 through 3.1.1 contains an authentication bypass vulnerability that allows unauthenticated remote attackers to forge administrative JWTs by using a hardcoded fallback signing secret when JWT_SECRET is unset. Attackers can sign tokens with arbitrary role, userGroups and permissions claims, which JwtStrategy.validate() trusts without a database lookup, to take control of pipelines, applications, users and API tokens.

Weakness: CWE-321 (Use of Hard-coded Cryptographic Key)

## Which versions are affected by CVE-2026-125370?


## How do I fix CVE-2026-125370?

No fix has been published for CVE-2026-125370 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-125370 being exploited?

There is no known exploitation of CVE-2026-125370 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-125370 and fix it if it is affected.

What it is: CVE-2026-125370 is a critical vulnerability in kubero-dev kubero, published on 9 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-125370 in the wild and no public exploit code.

Affected product: kubero-dev kubero. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-125370/ (Markdown: https://insights.sbomify.com/CVE-2026-125370/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-125370
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-125370
- OSV: https://osv.dev/vulnerability/CVE-2026-125370

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-125370/
Summaries are generated and may contain mistakes; the official description above is the record.