NixOS's Onlyoffice is a software suite that offers online and offline tools for document editing, collaboration, and management. In versions from 22.11 to before 25.05 and versions before Unstable 25.11, a hard-coded secret was used in the NixOS module for the OnlyOffice document server to protect its file cache. An attacker with knowledge of an existing revision ID could use this secret to obtain a document. In practice, an arbitrary revision ID should be hard to obtain. The primary impact is likely the access to known documents from users with expired access. This issue was resolved in NixOS unstable version 25.11 and version 25.05.
Conclusion & alert: CVE-2025-64766 is rated Low Risk (25.1/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.04%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-04-15 | 0.06% | 0.04% | -0.02% |
| 2 | 2026-03-19 | 0.03% | 0.06% | +0.03% |
| 3 | 2025-11-18 | — | 0.03% | — |
Full EPSS history (3 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.3 | 3.1 | MEDIUM |
|
3.9 | 1.4 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| No affected products in dataset. | |||