Auth bypass in Aces Loris

CVE-2026-34985

LORIS (Longitudinal Online Research and Imaging System) is a self-hosted web application that provides data- and project-management for neuroimaging research. From 16.1.0 to before 27.0.3 and 28.0.1, While the frontend of the media module filters files that the user should not have access to, the backend was not applying access checks and it would be possible for someone who should not have access to a file to access it if they know the filename. This vulnerability is fixed in 27.0.3 and 28.0.1.

Vulnerability class: IDOR (Insecure Direct Object Reference)

EPSS: 0.002 (13.5th 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:N/S:U/C:L/I:L/A:L.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-34985?
CVE-2026-34985 is a medium-severity vulnerability in Aces Loris, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 6.3/10. Published 2026-04-08.
How severe is CVE-2026-34985?
Medium severity. CVSS v3 base score is 6.3 out of 10.