What is CVE-2021-3776?

CVE-2021-3776 is a medium-severity vulnerability in Showdoc, classified under Cross-Site Request Forgery (CSRF). CVSS score: 5.4/10. Published 2021-11-13.

How severe is CVE-2021-3776?

Medium severity. CVSS v3 base score is 5.4 out of 10.

CSRF in Showdoc

CVE-2021-3776

showdoc is vulnerable to Cross-Site Request Forgery (CSRF)

Vulnerability class: CSRF (Cross-Site Request Forgery)

Published 2021-11-13 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (33.0th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

Showdoc
Star7th Star7th/showdoc — versions unspecified

Weakness classification (CWE)

CWE-352 — Cross-Site Request Forgery (CSRF)

References

huntr.dev/bounties/e0edf27d-437e-44fe-907a-df020f385304 (Exploit, Patch, Third Party Advisory)
github.com/star7th/showdoc/commit/67093c879a6563aa6ee08003177777d1975e2351 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-3776?: CVE-2021-3776 is a medium-severity vulnerability in Showdoc, classified under Cross-Site Request Forgery (CSRF). CVSS score: 5.4/10. Published 2021-11-13.
How severe is CVE-2021-3776?: Medium severity. CVSS v3 base score is 5.4 out of 10.