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TI-2026-30647 Aliases CVE-2026-42344

FastGPT: DNS rebinding TOCTOU bypass in isInternalAddress allows SSRF on all protected endpoints

Priority MEDIUM 61CWE-367Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
High · None · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

FastGPT is an AI Agent building platform. In versions 4.14.11 and prior, FastGPT's isInternalAddress() function in packages/service/common/system/utils.ts is vulnerable to DNS rebinding (TOCTOU — Time-of-Check to Time-of-Use). The function resolves the hostname via dns.resolve4()/dns.resolve6() and checks resolved IPs against private ranges, but the actual HTTP request happens in a separate call with a new DNS resolution, allowing the DNS record to change between validation and fetch. At time of publication, there are no publicly available patches.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00148 4th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
labringFastGPTup to 4.14.11—No fix listedCNA
  • FastGPT Vendorlabring Affected up to 4.14.11 Fixed in — No fix listed CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:fastgpt:fastgpt:*:*:*:*:*:*:*:*——Fastgpt
  • cpe:2.3:a:fastgpt:fastgpt:*:*:*:*:*:*:*:* Versions — — ·Fastgpt

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-42344

References

Other 1

  • 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-2026-44161 FastGPT: Unauthenticated cross-tenant data access via forgeable plugin-invoke JWT (default INVOKE_TOKEN_SECRET='token') CVSS 4.0HIGH 8.8
  • 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
See all 18 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences