Vulnerability · Published Sep 22, 2026 · Assigned by GitHub_M
CVE-2026-77637Cloudreve: Privilege Scope Bypass: State-Mutating Admin Operations Accessible via Read-Only OAuth Scope
Low 3.8
In plain English
A low-severity missing authorization in cloudreve from cloudreve. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% 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 4.18.0, tool.GET("wopi") and tool.POST("mail") in routers/router.go inherit ScopeAdminRead but omit the RequiredScopes(types.ScopeAdminWrite) middleware applied to neighboring state-changing admin tool routes. An OAuth application or API key limited to Admin.Read can therefore probe configured WOPI service endpoints and send arbitrary test email through the server SMTP configuration, exceeding the token's intended read-only authorization boundary. This issue is fixed in version 4.18.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/cloudreve/Cloudreve | no fix listed | GO-2026-6576 |
| Go | github.com/cloudreve/Cloudreve/v3 | no fix listed | GO-2026-6576 |
| Go | github.com/cloudreve/Cloudreve/v4 | 4.0.0-20260715070110-bce08f88e9d8 | GHSA-w89x-c962-c44g |
| Go | github.com/cloudreve/Cloudreve/v4 | 4.0.0-20260715070110-bce08f88e9d8 | GO-2026-6576 |
Affected products (as reported)
Weakness: CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N