CVE-2026-35403 LORIS has potential cross-site scripting in survey_accounts module
Attackers can execute arbitrary scripts in victim browsers via invalid visit labels due to missing Content-Type headers in LORIS.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-35403?
CVE-2026-35403 is a medium-severity cross-site scripting vulnerability in aces Loris, published on 8 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
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 15.10 to before 27.0.3 and 28.0.1, there is a potential for a cross-site scripting attack in the survey_accounts module if a user provides an invalid visit label. While the data is properly JSON encoded, the Content-Type header is not set causing the web browser to interpret the payload as HTML, opening the possibility of a cross-site scripting if a user is tricked into following an invalid link. This vulnerability is fixed in 27.0.3 and 28.0.1.
Weakness: CWE-79
Which versions are affected by CVE-2026-35403?
It affects 1 product.
Products include Mcgill Loris.
How do I fix CVE-2026-35403?
No fix has been published for CVE-2026-35403 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-35403 being exploited?
There is no known exploitation of CVE-2026-35403 in the wild and no public exploit code.
Other vulnerabilities in aces Loris
- CVE-2026-35169 LORIS has potential cross-site scripting in help_editor module
- CVE-2026-26984 LORIS media module vulnerable to remote code execution
- CVE-2026-26985 LORIS vulnerable to path traversal in electrophysiology_browser
- CVE-2026-35446 LORIS has a path traversal in FilesDownloadHandler
- CVE-2026-33350 LORIS has a SQL injection in MRI feedback popup
Sources
Also known as GHSA-776p-5pwh-vc8p.