What’s Vulnerable › Vulnerabilities

CVE-2023-34939

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 5.0% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2023-06-22 · updated 2026-06-17
• Weakness: CWE-22

Description

Onlyoffice Community Server before v12.5.2 was discovered to contain a remote code execution (RCE) vulnerability via the component UploadProgress.ashx.

Affected products

• Onlyoffice: before 12.5.2 — fixed in 12.5.2

How to fix

Upgrade to a fixed version: Onlyoffice 12.5.2. Check the vendor advisory for mitigations.

References

• https://github.com/ONLYOFFICE/CommunityServer/blob/master/CHANGELOG.md#version-1252
• https://github.com/firsov/onlyoffice
• https://github.com/firsov/onlyoffice/blob/main/CVE-2023-34939-PoC.md
• https://github.com/ONLYOFFICE/CommunityServer/blob/master/CHANGELOG.md#version-1252
• https://github.com/firsov/onlyoffice
• https://github.com/firsov/onlyoffice/blob/main/CVE-2023-34939-PoC.md

Get alerted when CVE-2023-34939 or the next vulnerability affects your stack