CVE-2026-55502: 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

highCVSS 7.1CVE-2026-55502

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.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: high — CVSS 7.1
Published: 2026-07-31
Last updated: 2026-07-31
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-55502

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-555020.34% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 26% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-55502	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

highGHSA-hq88-5x99-x3gf: Cloudreve OAuth Admin.Read scope can update OneDrive storage policy credentialsghsa

Recent advisories for Cloudreve is a

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

mediumCVE-2026-62323: Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, ViewerSessionV…nvd · 2026-07-31
mediumCVE-2026-55499: Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, a single-file …nvd · 2026-07-31
mediumCVE-2026-55497: Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, the built-in t…nvd · 2026-07-31
mediumCVE-2026-55496: Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, GET /api/v4/us…nvd · 2026-07-31
mediumCVE-2026-55495: Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, the WOPI PUT_R…nvd · 2026-07-31
mediumGHSA-v6w6-358x-2433: Cloudreve Admin.Read OAuth tokens can trigger server-side node test requestsghsa · 2026-07-24