CVE-2021-3199

ONLYOFFICE Docs Server Path Traversal Vulnerability

ONLYOFFICE Docs

CVSS

9.8Critical

ExploitationExploited in the wildAdded to KEV 8 Oct 2026CISA KEV

Exploit odds (EPSS)20.1%Chance of exploitation activity in the next 30 days, higher than 97% of CVEs. Scored 23 Oct 2026FIRST EPSS

Fixed inNone listedNo source names a fixed version. Check the vendor advisory below

Federal deadline11 Oct 2026Remediation due date for US federal agenciesCISA KEV

CISA required actionApply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. CISA KEV

Patching is not enoughCISA requires federal agencies to look for signs of compromise on affected systems, not only patch (forensic triage under BOD 26-04). Treat exposed systems as possibly compromised. CISA guidance

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Timeline

22 Jan 2021, 02:41 UTCPublishedCVE List
8 Oct 2026Added to CISA KEVCISA KEV

Description

ONLYOFFICE Docs contains a path traversal vulnerability that can occur when JWT is used, via a /.. sequence in an image upload parameter and could allow for remote code execution.

Text from CVE List

Affected versions 1

n/aaffected: n/aCVE List