What is CVE-2021-31646?

CVE-2021-31646 is a critical-severity vulnerability in Gestsup, classified under Improper Restriction of Excessive Authentication Attempts. CVSS score: 9.8/10. Published 2021-04-26.

How severe is CVE-2021-31646?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Gestsup

CVE-2021-31646

Gestsup before 3.2.10 allows account takeover through the password recovery functionality (remote). The affected component is the file forgot_pwd.php - it uses a weak algorithm for the generation of password recovery tokens (the PHP uniqueid function), allowing a brute force attack.

Published 2021-04-26 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.013 (70.2th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 70th percentile — 70.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: 0.000

Affected products

Gestsup

Weakness classification (CWE)

CWE-307 — Improper Restriction of Excessive Authentication Attempts

References

gestsup.fr/index.php (Patch, Vendor Advisory)
dojo.maltem.ca/public/advisories/CVE-2021-31646.html (Third Party Advisory, Broken Link)
gestsup.fr/index.php (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-31646?: CVE-2021-31646 is a critical-severity vulnerability in Gestsup, classified under Improper Restriction of Excessive Authentication Attempts. CVSS score: 9.8/10. Published 2021-04-26.
How severe is CVE-2021-31646?: Critical severity. CVSS v3 base score is 9.8 out of 10.