---
id: "CVE-2026-125370"
page: "https://infrastack.ai/live/CVE-2026-125370"
kind: "vulnerability"
aliases: ["CVE-2026-125370"]
title: "Kubero: hardcoded fallback JWT secret lets attackers forge admin tokens"
severity: "critical"
cvss: 9.8
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "kubernetes", "kubero", "self-hosted"]
not_affected_if: ["jwt-secret-set", "unaffected-version"]
published_at: "2026-11-10T00:17:09+00:00"
first_seen_at: "2026-11-10T00:28:42+00:00"
updated_at: "2026-11-10T00:29:42+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-125370", "first_seen_at": "2026-11-10T00:28:42+00:00"}]
exploit_sources: []
---

# Kubero: hardcoded fallback JWT secret lets attackers forge admin tokens

Link for people: https://infrastack.ai/live/CVE-2026-125370 (this .md is for agents)

Kubero 3.0.0 through 3.1.1 falls back to a hardcoded signing secret when JWT_SECRET is unset, so anyone can forge administrative JSON Web Tokens. A forged token lets an unauthenticated remote attacker take control of pipelines, applications, users and API tokens.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check whether the `JWT_SECRET` environment variable is set on the Kubero deployment; if it is unset, the hardcoded fallback is in use.
- Check the installed Kubero version; versions `3.0.0` through `3.1.1` are affected.

## Fix

- Kubero: the sources do not state a fixed version.

## Timeline

- 2026-11-10T00:28:42+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-125370

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/kubero-3.0.0-through-3.1.1-authentication-bypass-via-hardcoded-jwt-secret

## From the sources

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.

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