Auth bypass in Cloudreve
CVE-2026-62323
Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, ViewerSessionValidation uses only the session-id prefix of a WOPI access token and does not enforce the requested viewer action, allowing a malicious or compromised WOPI viewer with a view session to forge the token suffix and invoke WOPI write routes for the underlying file. This issue is fixed in version 4.17.0.
Vulnerability class: Broken Access Control
EPSS: 0.002 (6.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:N.
Affected products
- Cloudreve — versions < 4.17.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_CONFIRM)
Frequently asked questions
- What is CVE-2026-62323?
- CVE-2026-62323 is a medium-severity vulnerability in Cloudreve, classified under Incorrect Authorization. CVSS score: 6.3/10. Published 2026-07-31.
- How severe is CVE-2026-62323?
- Medium severity. CVSS v3 base score is 6.3 out of 10.