CVE-2026-61684: CWE-798: Use of Hard-coded Credentials in labring FastGPT
FastGPT is a knowledge-based AI application platform. In 4.15.0-beta4, FastGPT plugin invoke reverse-call endpoints under /api/invoke/* authenticate only by verifying a JWT signed with INVOKE_TOKEN_SECRET, which defaults to the constant string token and was not set in official deployment templates. An unauthenticated attacker can self-sign an HS256 JWT and reach /api/invoke/userInfo to disclose cross-tenant user PII by attacker-supplied tmbId values, or /api/invoke/fileUpload to write attacker-controlled content into chat files. This issue is fixed in version 4.15.0-beta5.
AI Analysis
Technical Summary
FastGPT 4.15.0-beta4 uses a hard-coded secret (INVOKE_TOKEN_SECRET) for signing JWT tokens to authenticate access to reverse-call endpoints under /api/invoke/*. Because the secret defaults to a constant string and is not set in official deployment templates, attackers can create valid HS256 JWTs without authentication. This allows them to call /api/invoke/userInfo to access PII across tenants by supplying arbitrary tmbId values, and /api/invoke/fileUpload to write attacker-controlled content into chat files. The vulnerability is classified as CWE-798 (Use of Hard-coded Credentials). It is resolved in FastGPT 4.15.0-beta5.
Potential Impact
An unauthenticated attacker can bypass authentication by self-signing JWT tokens using the hard-coded secret, leading to unauthorized access to sensitive user information across tenants and the ability to upload arbitrary files. This compromises confidentiality and integrity of user data and application files.
Mitigation Recommendations
A fix is available in FastGPT version 4.15.0-beta5 that removes the use of the hard-coded secret and properly secures the JWT authentication mechanism. Users should upgrade to this version or later to remediate the vulnerability. No official patch or temporary fix is indicated beyond upgrading. Since this is not a cloud service, remediation depends on user action.
CVE-2026-61684: CWE-798: Use of Hard-coded Credentials in labring FastGPT
Description
FastGPT is a knowledge-based AI application platform. In 4.15.0-beta4, FastGPT plugin invoke reverse-call endpoints under /api/invoke/* authenticate only by verifying a JWT signed with INVOKE_TOKEN_SECRET, which defaults to the constant string token and was not set in official deployment templates. An unauthenticated attacker can self-sign an HS256 JWT and reach /api/invoke/userInfo to disclose cross-tenant user PII by attacker-supplied tmbId values, or /api/invoke/fileUpload to write attacker-controlled content into chat files. This issue is fixed in version 4.15.0-beta5.
CVSS v4.0
Score 8.8high
Affected software
pkg:github/labring/FastGPTRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
FastGPT 4.15.0-beta4 uses a hard-coded secret (INVOKE_TOKEN_SECRET) for signing JWT tokens to authenticate access to reverse-call endpoints under /api/invoke/*. Because the secret defaults to a constant string and is not set in official deployment templates, attackers can create valid HS256 JWTs without authentication. This allows them to call /api/invoke/userInfo to access PII across tenants by supplying arbitrary tmbId values, and /api/invoke/fileUpload to write attacker-controlled content into chat files. The vulnerability is classified as CWE-798 (Use of Hard-coded Credentials). It is resolved in FastGPT 4.15.0-beta5.
Potential Impact
An unauthenticated attacker can bypass authentication by self-signing JWT tokens using the hard-coded secret, leading to unauthorized access to sensitive user information across tenants and the ability to upload arbitrary files. This compromises confidentiality and integrity of user data and application files.
Mitigation Recommendations
A fix is available in FastGPT version 4.15.0-beta5 that removes the use of the hard-coded secret and properly secures the JWT authentication mechanism. Users should upgrade to this version or later to remediate the vulnerability. No official patch or temporary fix is indicated beyond upgrading. Since this is not a cloud service, remediation depends on user action.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-07-10T18:36:58.849Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a579dd068715ace43e954c8
Added to database: 07/15/2026, 14:48:48 UTC
Last enriched: 07/15/2026, 15:03:30 UTC
Last updated: 07/16/2026, 01:48:02 UTC
Views: 10
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