FastGPT: Unauthenticated cross-tenant data access via forgeable plugin-invoke JWT (default INVOKE_TOKEN_SECRET='token')
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-798.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-61684
References
More labring vulnerabilities
- TI-2026-30610 FastGPT: Unauthenticated Remote Code Execution (RCE) via code-server Misconfiguration in agent-sandbox CVSS 3.1CRITICAL 9.8
- TI-2026-48466 FastGPT: Unauthenticated WeChat channel hijack and denial of service via shareId-only authorization CVSS 4.0CRITICAL 9.3
- TI-2026-44148 Incorrect authorization in labring FastGPT CVSS 3.1HIGH 7.7
- TI-2026-39440 FastGPT: SSRF in HTTP-tool OpenAPI schema importer via SwaggerParser $ref (bypasses the isInternalAddress guard) CVSS 3.1HIGH 7.7
- TI-2026-30646 FastGPT: Uncontrolled Resource Consumption leading to Sandbox Exhaustion CVSS 4.0MEDIUM 6.3
- TI-2026-57936 FastGPT safe axios SSRF guard still allows DNS rebinding TOCTOU on protected outbound requests CVSS 3.1MEDIUM 6.3
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences