What is CVE-2026-40252?

CVE-2026-40252 is a high-severity vulnerability in Fastgpt, classified under Improper Access Control. CVSS score: 8.1/10. Published 2026-04-10.

How severe is CVE-2026-40252?

High severity. CVSS v3 base score is 8.1 out of 10.

Auth bypass in Fastgpt

CVE-2026-40252

FastGPT is an AI Agent building platform. Prior to 4.14.10.4, Broken Access Control vulnerability (IDOR/BOLA) allows any authenticated team to access and execute applications belonging to other teams by supplying a foreign appId. While the API correctly validates the team token, it does not verify that the requested application belongs to the authenticated team. This leads to cross-tenant data exposure and unauthorized execution of private AI workflows. This vulnerability is fixed in 4.14.10.4.

Published 2026-04-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.003 (27.8th percentile), scored 2026-09-23.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 27.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Fastgpt
Labring Fastgpt — versions < 4.14.10.4

Weakness classification (CWE)

References

github.com/labring/FastGPT/security/advisories/GHSA-gc8m-w37w-24hw (Vendor Advisory)
github.com/labring/FastGPT/releases/tag/v4.14.10.4 (Release Notes)

Frequently asked questions

What is CVE-2026-40252?: CVE-2026-40252 is a high-severity vulnerability in Fastgpt, classified under Improper Access Control. CVSS score: 8.1/10. Published 2026-04-10.
How severe is CVE-2026-40252?: High severity. CVSS v3 base score is 8.1 out of 10.