Vulnerability · Published Jul 31, 2026 · Assigned by GitHub_M

CVE-2026-55502Cloudreve: OAuth Admin.Read scope can update OneDrive storage policy credentials

High 7.1

In plain English

A high-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 27% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.1High

Exploit odds (30 days)0.3%top 72.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	github.com/cloudreve/Cloudreve	no fix listed	GO-2026-6101
Go	github.com/cloudreve/Cloudreve/v3	no fix listed	GHSA-hq88-5x99-x3gf
Go	github.com/cloudreve/Cloudreve/v3	no fix listed	GO-2026-6101
Go	github.com/cloudreve/Cloudreve/v4	4.17.0	GHSA-hq88-5x99-x3gf
Go	github.com/cloudreve/Cloudreve/v4	no fix listed	GO-2026-6101

Affected products (as reported)

Vendor	Product	Versions
cloudreve	cloudreve	< 4.17.0

Weakness: CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L

References

https://github.com/cloudreve/cloudreve/security/advisories/GHSA-hq88-5x99-x3gf x_refsource_CONFIRM