What is CVE-2020-21865?

CVE-2020-21865 is a critical-severity vulnerability in Thinkphp50-Cms Project. CVSS score: 9.8/10. Published 2021-10-07.

How severe is CVE-2020-21865?

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

Vulnerability in Thinkphp50-Cms Project

CVE-2020-21865

ThinkPHP50-CMS v1.0 contains a remote code execution (RCE) vulnerability in the component /public/?s=captcha.

Published 2021-10-07 · 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: 0.020 (80.1th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 80th percentile — 80.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.020 · newest: 0.020 · change: 0.000

Affected products

Thinkphp50-Cms Project — versions 1.0

References

github.com/nnngu/ThinkPHP50-CMS/issues/1 (Third Party Advisory)

Frequently asked questions

What is CVE-2020-21865?: CVE-2020-21865 is a critical-severity vulnerability in Thinkphp50-Cms Project. CVSS score: 9.8/10. Published 2021-10-07.
How severe is CVE-2020-21865?: Critical severity. CVSS v3 base score is 9.8 out of 10.