RCE in Ascensio System Sia Onlyoffice
CVE-2025-10254
A vulnerability was found in Ascensio System SIA OnlyOffice up to 12.7.0. This issue affects some unknown processing of the file /Products/Projects/Messages.aspx of the component SVG Image Handler. Performing manipulation results in cross site scripting. The attack may be initiated remotely. The exploit has been made public and could be used. The vendor was informed early about this issue and replied: "We are already working on this case, and the issues will be resolved in one of the upcoming patches."
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.5 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (17.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 17.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Ascensio System Sia Onlyoffice — versions 12.0, 12.1, 12.2
Weakness classification (CWE)
References
- vuldb.com/ (vdb-entry)
- vuldb.com/ (signature, permissions-required)
- vuldb.com/ (third-party-advisory)
- hkohi.ca/vulnerability/20 (exploit)
Frequently asked questions
- What is CVE-2025-10254?
- CVE-2025-10254 is a low-severity vulnerability in Ascensio System Sia Onlyoffice, classified under Cross-site Scripting. CVSS score: 3.5/10. Published 2025-09-11.
- How severe is CVE-2025-10254?
- Low severity. CVSS v3 base score is 3.5 out of 10.