Auth bypass in Lycheeorg Lychee
CVE-2026-39957
Lychee is a free, open-source photo-management tool. Prior to 7.5.4, a SQL operator-precedence bug in SharingController::listAll() causes the orWhereNotNull('user_group_id') clause to escape the ownership filter applied by the when() block. Any authenticated non-admin user with upload permission who owns at least one album can retrieve all user-group-based sharing permissions across the entire instance, including private albums owned by other users. This vulnerability is fixed in 7.5.4.
Vulnerability class: Broken Access Control
EPSS: 0.002 (11.1th 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
- Lycheeorg Lychee — versions < 7.5.4
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Patch, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-39957?
- CVE-2026-39957 is a medium-severity vulnerability in Lycheeorg Lychee, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2026-04-09.
- How severe is CVE-2026-39957?
- Medium severity. CVSS v3 base score is 4.3 out of 10.