CVE-2025-51606Public exploitNetwork attack vector

Administrator impersonation via hard-coded JWT secret

Published Aug 21, 2025 · Updated Aug 22, 2025

Authentication bypass in Hippo4J 1.0.0 through 1.5.0 allows remote authenticated users to impersonate administrators with forged JWTs. JwtTokenManager signs HS512 tokens with a constant SECRET embedded in JwtTokenUtil, so any subject claim signed with that value is accepted as authentic. Access to the source code or compiled binary reveals the key, and a forged admin token grants the protected API permissions assigned to that account.

CVSS severity8.8
High
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Hippo4J 1.0.0 through 1.5.0 allows remote authenticated users to impersonate administrators with forged JWTs. JwtTokenManager signs HS512 tokens with a constant SECRET embedded in JwtTokenUtil, so any subject claim signed with that value is accepted as authentic. Access to the source code or compiled binary reveals the key, and a forged admin token grants the protected API permissions assigned to that account.

The record

CVE
CVE-2025-51606
Published
Aug 21, 2025
Updated
Aug 22, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-798, T1606
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 21, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 22, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-798Use of Hard-coded Credentials
T1606Forge Web Credentials

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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