CISA KEV entry
CVE-2021-3199ONLYOFFICE Docs Server Path Traversal Vulnerability
ONLYOFFICE Docs. Added to the CISA Known Exploited Vulnerabilities catalogue on 8 October 2026.
Data status: a source is stale
Last synced CISA catalogue version 2026.11.04 (released 4 November 2026) 1,768 entries Updated manually
- Date added
- 2026-10-08
- Federal due date
- 2026-10-11 3 days after it was added; passed at the sync of 2026-11-05
- Known ransomware use
- Unknown
- Forensic triage (BOD 26-04)
- Yes
- CVSS
- 9.8 Critical CVSS 3.1, scored by nvd@nist.gov
- EPSS
- 30.24% percentile 98.2, scored 2026-11-04
- CISA SSVC
- Exploitation active, automatable yes, technical impact total
- NVD status
- Analyzed published 2021-01-26, 2081 days before the KEV listing
BOD 26-04 remediation window
With CISA's SSVC answers for this CVE (automatable: yes, technical impact: total), BOD 26-04 Table 1 gives 3 days and forensic triage on a publicly exposed asset (row 1) and 3 days and forensic triage on an asset that is not publicly exposed (row 9) S06. CISA set the catalogue due date at 3 days; under BOD 26-04 it reflects CISA's own view of whether the flaw sits on publicly exposed assets S07. The directive binds US federal civilian executive branch agencies only.
What CISA says
Short 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.
Required action
Apply 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.
Notes
This vulnerability could affect an open-source component, third-party library, protocol, or proprietary implementation that could be used by different products. For more information, please see: ; https://github.com/ONLYOFFICE/DocumentServer/blob/903fe5ab7a275bd69c3c3346af2d21cf87ebeabf/CHANGELOG.md#563 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2021-3199
CWE in the catalogue
CWE-22
Official links
- CISA KEV catalogue entry cisa.gov
- NVD record nvd.nist.gov
Vendor advisory and patch links
No vendor advisory linked by NVD.
Links in CISA's notes
- https://github.com/ONLYOFFICE/DocumentServer/blob/903fe5ab7a275bd69c3c3346af2d21cf87ebeabf/CHANGELOG.md#563
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- https://nvd.nist.gov/vuln/detail/CVE-2021-3199
NVD details
- CWE (NVD)
- CWE-22 by nvd@nist.gov
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- CVSS versions in NVD
- V2, V31
- Last modified in NVD
- 2026-10-09T14:20:47.350
Where each value comes from
| Field | Source | Fetched, UTC | State |
|---|---|---|---|
| Catalogue fields | CISA KEV JSON, version 2026.11.04 | 2026-11-05 11:38 | current |
| NVD published, status, CVSS, CWE, vendor links | NVD CVE API 2.0; CVSS: NVD (nvd@nist.gov) | 2026-11-03 12:37 | current at 2026-11-05 11:38 |
| EPSS | FIRST EPSS API, scores of 2026-11-04 | 2026-11-05 11:38 | current |
| CISA SSVC | CISA ADP (via NVD), record of 2026-10-08 | 2026-11-03 12:37 | current |
This product uses data from the NVD API but is not endorsed or certified by the NVD. CISA does not endorse Sysprobs. Methodology.
