CVE-2026-40100: CWE-918: Server-Side Request Forgery (SSRF) in labring FastGPT
FastGPT is an AI Agent building platform. Prior to 4.14.10.3, the /api/core/app/mcpTools/runTool endpoint accepts arbitrary URLs without authentication. The internal IP check in isInternalAddress() only blocks private IPs when CHECK_INTERNAL_IP=true, which is not the default. This allows unauthenticated attackers to perform SSRF against internal network resources. This vulnerability is fixed in 4.14.10.3.
AI Analysis
Technical Summary
CVE-2026-40100 is a medium-severity SSRF vulnerability in labring FastGPT before version 4.14.10.3. The vulnerability arises from the /api/core/app/mcpTools/runTool endpoint accepting arbitrary URLs without authentication. The internal IP filtering mechanism (isInternalAddress()) only blocks private IP addresses if the CHECK_INTERNAL_IP flag is set to true, but this flag is disabled by default. Consequently, unauthenticated attackers can exploit this to perform SSRF attacks targeting internal network resources. The vendor fixed this vulnerability in FastGPT version 4.14.10.3.
Potential Impact
An unauthenticated attacker can exploit this vulnerability to make the FastGPT server send arbitrary HTTP requests to internal network resources. This may allow attackers to access internal services that are not otherwise exposed externally. The CVSS score is 5.3 (medium severity) with impact limited to partial confidentiality loss and no integrity or availability impact. There are no known exploits in the wild at this time.
Mitigation Recommendations
Upgrade FastGPT to version 4.14.10.3 or later, where this SSRF vulnerability is fixed. If upgrading immediately is not possible, enable the CHECK_INTERNAL_IP setting to true to activate the internal IP address blocking as a temporary mitigation. Monitor vendor advisories for any additional guidance.
CVE-2026-40100: CWE-918: Server-Side Request Forgery (SSRF) in labring FastGPT
Description
FastGPT is an AI Agent building platform. Prior to 4.14.10.3, the /api/core/app/mcpTools/runTool endpoint accepts arbitrary URLs without authentication. The internal IP check in isInternalAddress() only blocks private IPs when CHECK_INTERNAL_IP=true, which is not the default. This allows unauthenticated attackers to perform SSRF against internal network resources. This vulnerability is fixed in 4.14.10.3.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-40100 is a medium-severity SSRF vulnerability in labring FastGPT before version 4.14.10.3. The vulnerability arises from the /api/core/app/mcpTools/runTool endpoint accepting arbitrary URLs without authentication. The internal IP filtering mechanism (isInternalAddress()) only blocks private IP addresses if the CHECK_INTERNAL_IP flag is set to true, but this flag is disabled by default. Consequently, unauthenticated attackers can exploit this to perform SSRF attacks targeting internal network resources. The vendor fixed this vulnerability in FastGPT version 4.14.10.3.
Potential Impact
An unauthenticated attacker can exploit this vulnerability to make the FastGPT server send arbitrary HTTP requests to internal network resources. This may allow attackers to access internal services that are not otherwise exposed externally. The CVSS score is 5.3 (medium severity) with impact limited to partial confidentiality loss and no integrity or availability impact. There are no known exploits in the wild at this time.
Mitigation Recommendations
Upgrade FastGPT to version 4.14.10.3 or later, where this SSRF vulnerability is fixed. If upgrading immediately is not possible, enable the CHECK_INTERNAL_IP setting to true to activate the internal IP address blocking as a temporary mitigation. Monitor vendor advisories for any additional guidance.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-09T01:41:38.536Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69d9d9721cc7ad14da3f864d
Added to database: 4/11/2026, 5:17:38 AM
Last enriched: 4/11/2026, 5:18:46 AM
Last updated: 4/11/2026, 3:05:09 PM
Views: 8
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