CVE-2026-34985 LORIS has incorrect access checks in media module

Medium 6.3 Published 8 Apr 2026 Updated 10 Apr 2026

Attackers can access unauthorized media files in LORIS by guessing filenames, bypassing frontend filters due to missing backend access checks.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-34985?

CVE-2026-34985 is a medium-severity missing authorization vulnerability in aces Loris, published on 8 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

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.

Weakness: CWE-639

Which versions are affected by CVE-2026-34985?

It affects 1 product.

Products include Mcgill Loris.

How do I fix CVE-2026-34985?

No fix has been published for CVE-2026-34985 yet. Limit exposure of the affected software until one is available.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-34985 being exploited?

There is no known exploitation of CVE-2026-34985 in the wild and no public exploit code.

Sources

Also known as GHSA-p42c-4gmq-hrjw.