Document Server vulnerabilitiesAnd the versions its exploited flaws hit.
Document Server is made by Onlyoffice. We track 19 published vulnerabilities in it, across 93 versions. 1 of them is on the list of flaws known to be exploited, the newest added on 8 October 2026. If you run Document Server, check your version against the exploited flaws below and patch those first.
The most recent Document Server flaw added to the known-exploited list is CVE-2021-3199, on 8 October 2026. We keep watching the known-exploited list.
Which versions of Document Server do the exploited flaws hit?
Each exploited flaw lists the versions it affects, usually as ranges. "before 5.6.3" means every version up to, but not including, 5.6.3. Find your version, then patch.
- CVE-2021-3199Exploited list, 8 Oct 2026
ONLYOFFICE Docs Server Path Traversal Vulnerability
before 5.6.3
Which Document Server vulnerabilities are being exploited?
1 flaw is on the government list of vulnerabilities known to be exploited. These are the ones criminals are using now, so they go first, whatever their severity score says.
- 9.8ONLYOFFICE Docs Server Path Traversal Vulnerability
ONLYOFFICE Docs contains a path traversal vulnerability that can occur when JWT is used, via a /..
Which Document Server flaws are most likely to be used?
Ranked by the latest exploit-likelihood forecast: the chance each flaw is used in an attack in the next 30 days. A high severity score on its own doesn't tell you that. Flaws shared by many other makers' products are left out.
- 44%CVE-2021-25833Critical
A file extension handling issue was found in [server] module of ONLYOFFICE DocumentServer v4.2.0.71-v5.6.0.21.
- 19%
Directory traversal with remote code execution can occur in /upload in ONLYOFFICE Document Server before 5.6.3, when JWT is used, via a /..
- 13%CVE-2021-25832Critical
A heap buffer overflow vulnerability inside of BMP image processing was found at [core] module of ONLYOFFICE DocumentServer v4.0.0-9-v6.0.0.
- 12%CVE-2021-25830Critical
A file extension handling issue was found in [core] module of ONLYOFFICE DocumentServer v4.2.0.236-v5.6.4.13.
- 12%CVE-2021-25831Critical
A file extension handling issue was found in [core] module of ONLYOFFICE DocumentServer v4.0.0-9-v5.6.3.
- 7.4%CVE-2021-25829High
An improper binary stream data handling issue was found in the [core] module of ONLYOFFICE DocumentServer v4.0.0-9-v5.6.3.
- 6.9%CVE-2022-29776Critical
Onlyoffice Document Server v6.0.0 and below and Core 6.1.0.26 and below were discovered to contain a stack overflow via the component DesktopEditor/common/File.cpp.
- 6.9%CVE-2022-29777Critical
Onlyoffice Document Server v6.0.0 and below and Core 6.1.0.26 and below were discovered to contain a heap overflow via the component DesktopEditor/fontengine/fontconverter/FontFileBase.h.
- 2.6%CVE-2020-11536Critical
An issue was discovered in ONLYOFFICE Document Server 5.5.0.
- 2.4%CVE-2023-30187Critical
An out of bounds memory access vulnerability in ONLYOFFICE DocumentServer 4.0.3 through 7.3.2 allows remote attackers to run arbitrary code via crafted JavaScript file.
Running Document Server? We'll keep checking.
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1 flaw being exploited affects software Acme tracks
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.
- Matched to
- Document Server on Acme's software list
- What to do
- Patch first, then check for signs of use
Sent to the alert recipients Acme chose. Also in the app and to Acme's webhook.
We track 19 published vulnerabilities listed under the name Document Server, across 93 versions. The most recent Document Server flaw added to the known-exploited list is CVE-2021-3199, on 8 October 2026.
1 is on the list of flaws known to be exploited. The most recently added is CVE-2021-3199.
Each flaw names its own versions, usually as ranges. The newest, CVE-2021-3199, affects before 5.6.3. The versions for every exploited flaw are listed on this page.
Create a Precursor Intelligence account and track Document Server. We match it against every published flaw, give each one a risk score from 0 to 100 and keep watching, so you hear about new ones as soon as we know, by email, in the app or by webhook.