CVE-2026-77637

Low

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.

SeverityLow
CVSS3.8
Exploit probability—
ProductGithub.com/cloudreve/cloudreve/v4
PublishedSep 22, 2026
First seenSep 22, 2026

How to fix

Update
  • github.com/cloudreve/Cloudreve/v44.0.0-20260715070110-bce08f88e9d8 or later

Affected products

ProductAffected versionsFixed in
github.com/cloudreve/Cloudreve/v4Gov < 4.0.0-20260715070110-bce08f88e9d84.0.0-20260715070110-bce08f88e9d8
github.com/cloudreve/CloudreveGoNo range specified—
github.com/cloudreve/Cloudreve/v3GoNo range specified—

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CVE-2026-77637 · Github.com/cloudreve/cloudreve/v4 · Dark Radar