---
id: CVE-2021-3199
title: >-
  Directory traversal with remote code execution can occur in /upload in
  ONLYOFFICE Document Server before 5.6.3, when JWT is used, via a /.
summary: >-
  Directory traversal with remote code execution can occur in /upload in
  ONLYOFFICE Document Server before 5.6.3, when JWT is used, via a /.. sequence
  in an image upload parameter.
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-22
vendor: onlyoffice
product: document_server
affected:
  - document_server < 5.6.3
patched:
  - document_server 5.6.3
published: '2021-01-26'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T18:17:12.203'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-3199'
references:
  - url: >-
      https://github.com/ONLYOFFICE/DocumentServer/blob/903fe5ab7a275bd69c3c3346af2d21cf87ebeabf/CHANGELOG.md#563
    label: cve@mitre.org
  - url: >-
      https://github.com/moehw/poc_exploits/tree/master/CVE-2021-3199/poc_uploadImageFile.py
    label: cve@mitre.org
  - url: >-
      https://github.com/nola-milkin/poc_exploits/blob/master/CVE-2021-3199/poc_uploadImageFile.py
    label: cve@mitre.org
  - url: >-
      https://github.com/ONLYOFFICE/DocumentServer/blob/903fe5ab7a275bd69c3c3346af2d21cf87ebeabf/CHANGELOG.md#563
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://github.com/moehw/poc_exploits/tree/master/CVE-2021-3199/poc_uploadImageFile.py
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://github.com/nola-milkin/poc_exploits/blob/master/CVE-2021-3199/poc_uploadImageFile.py
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-3199
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - in-the-wild
  - exploit-available
exploited: true
exploitAvailable: true
ssvc:
  exploitation: active
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-10-08T17:40:14.811565Z'
epss: 0.08215
epssPercentile: 0.94747
ingestedAt: '2026-10-08T17:56:11.729Z'
---

## Overview

Directory traversal with remote code execution can occur in /upload in ONLYOFFICE Document Server before 5.6.3, when JWT is used, via a /.. sequence in an image upload parameter.

## Affected

- `document_server < 5.6.3`

## Remediation

Upgrade past the affected range:

- `document_server 5.6.3`