# CVE-2025-51606: hippo4j Includes Hard Coded Secret Key in JWT Creation

> Attackers can forge valid JWTs using a hard-coded secret key to impersonate any user, including administrators, in applications using this library.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 Aug 2025
- **Updated:** 22 Aug 2025
- **Also known as:** GHSA-48cg-9c55-j2q7

## What is CVE-2025-51606?

CVE-2025-51606 is a high-severity vulnerability in n/a, published on 21 Aug 2025. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

hippo4j 1.0.0 to 1.5.0, uses a hard-coded secret key in its JWT (JSON Web Token) creation. This allows attackers with access to the source code or compiled binary to forge valid access tokens and impersonate any user, including privileged ones such as "admin". The vulnerability poses a critical security risk in systems where authentication and authorization rely on the integrity of JWTs.

Weakness: CWE-798 (Use of Hard-coded Credentials)

## Which versions are affected by CVE-2025-51606?

2 open source packages ship an affected version, including cn.hippo4j:hippo4j-core.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `cn.hippo4j:hippo4j-core` | Maven | From 1.0.0 to 1.5.0 | None |
| `cn.hippo4j:hippo4j-core` | Maven | From 1.0.0 to 1.5.0 | None |

## How do I fix CVE-2025-51606?

No fix has been published for CVE-2025-51606 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-51606 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-51606 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-51606 and fix it if it is affected.

What it is: CVE-2025-51606 is a high-severity vulnerability in n/a, published on 21 Aug 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-51606 exists.

Affected packages and fixed versions:
- cn.hippo4j:hippo4j-core (Maven): affected from 1.0.0 up to 1.5.0; no fix listed
- cn.hippo4j:hippo4j-core (Maven): affected from 1.0.0 up to 1.5.0; no fix listed

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-2025-51606/ (Markdown: https://insights.sbomify.com/CVE-2025-51606/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-51606
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-51606
- OSV: https://osv.dev/vulnerability/CVE-2025-51606

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-51606/
Summaries are generated and may contain mistakes; the official description above is the record.