What is CVE-2021-47936?

CVE-2021-47936 is a critical-severity vulnerability in Opencats, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2026-05-10.

How severe is CVE-2021-47936?

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

Auth bypass in Opencats

CVE-2021-47936

OpenCATS 0.9.4 contains a remote code execution vulnerability that allows unauthenticated attackers to execute arbitrary commands by uploading malicious PHP files disguised as resume attachments. Attackers can upload PHP payloads through t…

Vulnerability class: Broken Authentication

EPSS: 0.003 (53.1th percentile) — read the EPSS interpretation.

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.

Affected products

Opencats — versions 0

Weakness classification (CWE)

CWE-306 — Missing Authentication for Critical Function

References

disclosure@vulncheck.com (exploit)
disclosure@vulncheck.com (product)
disclosure@vulncheck.com (product)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2021-47936?: CVE-2021-47936 is a critical-severity vulnerability in Opencats, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2026-05-10.
How severe is CVE-2021-47936?: Critical severity. CVSS v3 base score is 9.8 out of 10.