CVE-2026-42345: Labring Fastgpt

High severity, CVSS 7.7. EPSS: 0.4% chance of exploitation in the next 30 days.

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.

Affected products

• Labring Fastgpt: up to and including 4.14.11

Published 2026-05-08. Last modified 2026-07-24.