---
id: CVE-2021-47936
title: >-
  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
summary: >-
  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…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-306
published: '2026-05-10'
updated: '2026-10-06'
sourceUpdated: '2026-10-06T22:10:00.247'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-47936'
references:
  - url: 'https://github.com/opencats/OpenCATS'
    label: disclosure@vulncheck.com
  - url: 'https://www.exploit-db.com/exploits/50585'
    label: disclosure@vulncheck.com
  - url: 'https://www.opencats.org/'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/opencats-remote-code-execution-via-resume-upload
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00656
epssPercentile: 0.49757
ingestedAt: '2026-10-06T22:23:15.921Z'
---

## Overview

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 the careers job application endpoint and execute system commands via POST requests to the uploaded file in the upload directory.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.