CVE-2026-55502

High

Description

Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, POST /api/v4/admin/policy/oauth/signin requires only Admin.Read even though GetOauthRedirectService persists caller-supplied OneDrive secret and app_id values, allowing an OAuth token without Admin.Write to modify storage policy credentials. The route is inside the admin group that requires Admin.Read, but it does not add the local Admin.Write guard used by sibling policy mutation routes. Its handler persists attacker-supplied secret and app_id values into the selected OneDrive storage policy before returning an OAuth URL. This issue is fixed in version 4.17.0.

SeverityHigh
CVSS7.1
Exploit probability—
ProductGithub.com/cloudreve/cloudreve/v4
PublishedJul 31, 2026
First seenJul 31, 2026

How to fix

Update
  • github.com/cloudreve/Cloudreve/v44.17.0 or later

Affected products

ProductAffected versionsFixed in
github.com/cloudreve/Cloudreve/v4Gov < 4.17.0, No range specified4.17.0
github.com/cloudreve/Cloudreve/v3Gov ≤ 3.0.0-20250225100611-da4e44b77af4, No range specified—
github.com/cloudreve/CloudreveGoNo range specified—

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