CVE-2026-55502 Cloudreve: OAuth Admin.Read scope can update OneDrive storage policy credentials
An attacker with Admin.Read scope can modify OneDrive storage policy credentials due to missing Admin.Write authorization checks on a specific API route.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-55502?
CVE-2026-55502 is a high-severity missing authorization vulnerability in cloudreve, published on 31 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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.
Weakness: CWE-863
Which versions are affected by CVE-2026-55502?
7 open source packages ship an affected version, including github.com/cloudreve/Cloudreve/v3, github.com/cloudreve/Cloudreve and github.com/cloudreve/Cloudreve/v4.
| Package | Affected | Fixed in |
|---|---|---|
github.com/cloudreve/Cloudreve/v3 Go | All versions | None |
github.com/cloudreve/Cloudreve/v3 Go | All versions to 3.0.0-20250225100611-da4e44b77af4 | None |
github.com/cloudreve/Cloudreve/v3 Go | All versions to 3.0.0-20250225100611-da4e44b77af4 | None |
github.com/cloudreve/Cloudreve Go | All versions | None |
github.com/cloudreve/Cloudreve/v4 Go | All versions | None |
github.com/cloudreve/Cloudreve/v4 Go | All versions | 4.17.0 |
1 more packages
github.com/cloudreve/Cloudreve/v4 Go | All versions | 4.17.0 |
How do I fix CVE-2026-55502?
Upgrade to a fixed version.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-55502 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55502 exists.
Sources
Also known as GHSA-hq88-5x99-x3gf, GO-2026-6101.