Cyber Posture

CVE-2026-26984

High

Published: 25 February 2026

Published
25 February 2026
Modified
05 March 2026
KEV Added
Patch
CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0016 37.1th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Description

LORIS (Longitudinal Online Research and Imaging System) is a self-hosted web application that provides data- and project-management for neuroimaging research. Prior to versions 26.0.5, 27.0.2, and 28.0.0, an authenticated user with sufficient privileges can exploit a path traversal vulnerability to…

more

upload a malicious file to an arbitrary location on the server. Once uploaded, the file can be used to achieve remote code execution (RCE). An attacker must be authenticated and have the appropriate permissions to exploit this issue. If the server is configured as read-only, remote code execution (RCE) is not possible; however, the malicious file upload may still be achievable. This problem is fixed in LORIS v26.0.5 and above, v27.0.2 and above, and v28.0.0 and above. As a workaround, LORIS administrators can disable the media module if it is not being used.

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly mitigates path traversal by validating uploaded file paths to confine them to authorized directories, preventing arbitrary file placement.

prevent

Enforces least functionality by disabling the unused media module, eliminating the vulnerable upload capability as recommended in the workaround.

prevent

Requires timely flaw remediation through patching to versions 26.0.5, 27.0.2, or 28.0.0 that fix the path traversal vulnerability.

Security SummaryAI

CVE-2026-26984 is a path traversal vulnerability (CWE-22, CWE-434) in LORIS, a self-hosted web application for data and project management in neuroimaging research. It affects versions prior to 26.0.5, 27.0.2, and 28.0.0, enabling an authenticated user with sufficient privileges to upload a malicious file to an arbitrary location on the server. This can lead to remote code execution (RCE) once the file is in place. The vulnerability carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

An attacker must be authenticated and possess the appropriate permissions to exploit this issue, targeting the media module. By leveraging the path traversal, they can place a malicious file anywhere on the server filesystem, potentially executing arbitrary code if the server processes it. In read-only configurations, RCE is prevented, though arbitrary file upload remains feasible.

The vulnerability is fixed in LORIS versions 26.0.5 and later, 27.0.2 and later, and 28.0.0 and later. As a workaround, administrators can disable the media module if it is not required. Details are available in the GitHub security advisory (GHSA-mpgc-c48m-6v2h) and release notes for the patched versions.

Details

CWE(s)

Affected Products

mcgill
loris
≤ 26.0.5 · 27.0.0 — 27.0.2

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Path traversal vulnerability in a self-hosted web application enables authenticated users to upload malicious files to arbitrary server locations, leading to RCE, directly facilitating exploitation of public-facing applications.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References