CVE-2026-42345 json
FastGPT: Cloud metadata endpoint SSRF protection bypass via port specification, IPv6 mapping, hex/decimal IP encoding, and trailing dot
published 6mo ago modified 3mo ago also EUVD-2026-28855
- cvss
- 7.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 11%
- public exploits
- 0
- none known
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 blocks cloud metadata endpoints using a fullUrl.startsWith() check against a hardcoded list. This check can be bypassed using at least 7 different URL encoding techniques, all of which resolve to the same cloud metadata service but do not match the blocklist patterns. Additionally, the broader private IP check (isInternalIPv4/isInternalIPv6) is disabled by default because CHECK_INTERNAL_IP defaults to false (not 'true'), so these bypasses reach the metadata endpoint without any further validation. At time of publication, there are no publicly available patches.
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Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 5mo ago
Exploit prediction
0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |
Affected products
- labring FastGPT
Classification
- Weakness
-
- CWE-918 Server-Side Request Forgery
References
Sources
- CVE List CVE-2026-42345
- NVD CVE-2026-42345
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.