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Not in CISA KEV
HIGH severity

CVE-2025-51606 — hippo4j-core

HIGH

CVE-2025-51606 is a high-severity (CVSS 8.8) Hard-coded Credentials vulnerability in cn.hippo4j:hippo4j-core. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.

hippo4j Includes Hard Coded Secret Key in JWT Creation

Published
Updated
Affected
1 pkg
Patched
None yet
Exploits
None indexed
Exploitation data as of Nov 1, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

  • CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
  • A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA’s SSVC triage for CVE-2025-51606.

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs29th percentile — riskier than 29% of all scored CVEsHighest risk
0.00%0.28%0.57%0.85%0.1%0.4%May 26Aug 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected
☕cn.hippo4j:hippo4j-core

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

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.

Affected Packages

1 total
EcosystemPackageVulnerable rangeFix
☕Mavencn.hippo4j:hippo4j-core≥ 1.0.0No fix

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for cn.hippo4j:hippo4j-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Remediation status

    The records we use list no patched version of cn.hippo4j:hippo4j-core for CVE-2025-51606. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.

  3. Mitigate without a patch

    Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

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.
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CVE-2025-51606: hippo4j-core (High 8.8)