Auth bypass in Cloudreve
CVE-2026-55499
Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, a single-file share event-stream subscription resolves the share root to the owner’s parent folder and subscribes to that folder topic, allowing an authenticated share recipient to receive names, paths, rename targets, event types, and hashed identifiers for unshared sibling files and folders. This issue is fixed in version 4.17.0.
Vulnerability class: Broken Access Control
EPSS: 0.002 (15.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/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-2026-55499?
- CVE-2026-55499 is a medium-severity vulnerability in Cloudreve, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2026-07-31.
- How severe is CVE-2026-55499?
- Medium severity. CVSS v3 base score is 4.3 out of 10.