CVE-2026-55418

FastGPT is an open source AI knowledge base platform. Prior to v4.15.0-beta5, two FastGPT file handlers authorize an unrelated resource and then sign or read an S3 object using a key taken directly from the request, without checking that the key belongs to the caller's team. Because S3 object keys are global within the bucket and carry the tenant id only as a path segment, an attacker can supply another team's key and obtain its file contents through the chat-file presign endpoint or dataset preview endpoint. This issue is fixed in version v4.15.0-beta5.

CVSS 3.1

8.6CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

EPSS

0.5% chance of exploitation in the next 30 days; higher than 41% of CVEs (scores of 2026-10-25)

CWE

CWE-639

Published

2026-07-07

Modified

2026-10-25

Record from

the NVD, synced 2026-10-25

References

• https://github.com/labring/FastGPT/commit/decb6d2fb1417fb9e2bca145d2dcc9cbcf06396c
• https://github.com/labring/FastGPT/pull/7104
• https://github.com/labring/FastGPT/releases/tag/v4.15.0-beta5
• https://github.com/labring/FastGPT/security/advisories/GHSA-6rxv-p43w-mmx5

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