ONLYOFFICE all versions as of 2021-11-08 is vulnerable to Cross Site Scripting (XSS).

published 2023-01-23 3 y ago modified 2026-06-17 4 mo ago also EUVD-2021-30379

cvss: 6.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 58%
public exploits: 0; none known

ONLYOFFICE all versions as of 2021-11-08 is vulnerable to Cross Site Scripting (XSS). The "macros" feature of the document editor allows malicious cross site scripting payloads to be used.

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 19 mo ago (2025-04-02)

Exploit prediction

0.84% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

labs.nettitude.com https://labs.nettitude.com/blog/exploiting-onlyoffice-web-sockets-for-unauthenticated-remote-code-execution/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
NVD	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CNA	3.1	6.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

labs.nettitude.com /blog/exploiting-onlyoffice-web-sockets-for-unauthenticated-remote-code-execution/
exploit, mitigation, third-party-advisory
onlyoffice.com /
product, vendor-advisory
github.com /ONLYOFFICE/server
third-party-advisory

Sources

CVE List CVE-2021-43446
NVD CVE-2021-43446

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary