What is CVE-2021-3976?

CVE-2021-3976 is a medium-severity vulnerability in Kevinpapst Kevinpapst/kimai2, classified under Cross-Site Request Forgery (CSRF). CVSS score: 6.5/10. Published 2021-11-19.

How severe is CVE-2021-3976?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Is CVE-2021-3976 known to be exploited?

3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

CSRF in Kevinpapst Kevinpapst/kimai2

CVE-2021-3976

kimai2 is vulnerable to Cross-Site Request Forgery (CSRF)

Vulnerability class: CSRF (Cross-Site Request Forgery)

Published 2021-11-19 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (31.6th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 32nd percentile — 31.6% 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

Kevinpapst Kevinpapst/kimai2 — versions unspecified
Kimai 2

Weakness classification (CWE)

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

Public proof-of-concept exploits

References

huntr.dev/bounties/0567048a-118c-42ec-9f94-b55533017406 (Exploit, Patch, Third Party Advisory, Issue Tracking)
github.com/kevinpapst/kimai2/commit/b28e9c120c87222e21a238f1b03a609d6a5d506e (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-3976?: CVE-2021-3976 is a medium-severity vulnerability in Kevinpapst Kevinpapst/kimai2, classified under Cross-Site Request Forgery (CSRF). CVSS score: 6.5/10. Published 2021-11-19.
How severe is CVE-2021-3976?: Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2021-3976 known to be exploited?: 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.