Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-26984 is a high-severity Path Traversal (CWE-22) vulnerability in Mcgill Loris. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 49th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
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.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-8746
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.3.2V5.1.1
Mitigating Controls (NIST 800-53 r5) AI
Enforces the intended directory access authorizations that path traversal would otherwise bypass.
Input validation directly neutralizes special path elements before pathname construction occurs.
Malicious-code protection at entry points blocks dangerous file types from being accepted and executed.
Least privilege reduces the impact of any unauthorized file access obtained via traversal.
Least functionality restricts the file types and automatic processing capabilities the system will accept.
Mobile-code controls define, authorize, and block unacceptable uploaded code before automatic processing occurs.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Restricting execution of unauthorized software directly blocks dangerous uploaded files from running.
Hardened configuration baselines can enforce allowed file types and processing rules.
Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.
Secure development practices include input validation and file-type restrictions that prevent this weakness.
PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development catches path traversal via static/dynamic analysis.
Secure SDLC mandates input validation and path sanitization that directly prevent path traversal.
Application security requirements include rules for safe file handling and canonicalization.
Secure architecture principles require least-privilege file access and directory isolation.
Secure coding standards explicitly forbid unsafe path construction and mandate safe APIs.
Information access restriction limits which files an application may read or write.