Vulnerability · Published Jul 31, 2026 · Assigned by GitHub_M
CVE-2026-62323Cloudreve: Unauthorized file write via WOPI view sessions whose access token secret is ignored
Medium 6.3
In plain English
A medium-severity incorrect authorization in cloudreve from cloudreve. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, ViewerSessionValidation uses only the session-id prefix of a WOPI access token and does not enforce the requested viewer action, allowing a malicious or compromised WOPI viewer with a view session to forge the token suffix and invoke WOPI write routes for the underlying file. This issue is fixed in version 4.17.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/cloudreve/Cloudreve | no fix listed | GO-2026-6104 |
| Go | github.com/cloudreve/Cloudreve/v3 | no fix listed | GHSA-c3jm-gv5r-9wcp |
| Go | github.com/cloudreve/Cloudreve/v3 | no fix listed | GO-2026-6104 |
| Go | github.com/cloudreve/Cloudreve/v4 | 4.0.0-20260626022433-f3347130ac48 | GHSA-c3jm-gv5r-9wcp |
| Go | github.com/cloudreve/Cloudreve/v4 | 4.0.0-20260626022433-f3347130ac48 | GO-2026-6104 |
Affected products (as reported)
Weakness: CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:N