XSS in Fastgpt

CVE-2025-52552

FastGPT is an AI Agent building platform. Prior to version 4.9.12, the LastRoute Parameter on login page is vulnerable to open redirect and DOM-based XSS. Improper validation and lack of sanitization of this parameter allows attackers execute malicious JavaScript or redirect them to attacker-controlled sites. This issue has been patched in version 4.9.12.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (16.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 17th percentile — 16.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-52552: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-52552?
CVE-2025-52552 is a medium-severity vulnerability in Fastgpt, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2025-06-21.
How severe is CVE-2025-52552?
Medium severity. CVSS v3 base score is 6.1 out of 10.