LorisApplication · Mcgill

CVE-2026-35169

MEDIUM · 5.4 CVSS v3.1 Published 2026-04-08
Fix available
A fix is available. Upgrade to after 27.0.2 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
LORIS (Longitudinal Online Research and Imaging System) is a self-hosted web application that provides data- and project-management for neuroimaging research. From to before 27.0.3 and 28.0.1, the help_editor module of LORIS did not properly sanitize some user supplied variables which could result in a reflected cross-site scripting attack if a user is tricked into following an invalid link. The same input vector could also allow an attacker to download arbitrary markdown files on an unpatched server. This vulnerability is fixed in 27.0.3 and 28.0.1.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

The help_editor module in LORIS does not properly sanitize user-supplied variables, leading to reflected cross-site scripting (XSS) when users are tricked into following a maliciously crafted link. The same insufficient input validation also allows attackers to download arbitrary markdown files from the server.

MitigationUpgrade LORIS to version 27.0.3 or 28.0.1 or later to receive the patch for the help_editor module's input sanitization issues.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
LorisApplication
Affected:>= 15.10, <= 27.0.2= 28.0.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed LORIS version
    Check the LORIS version by inspecting the version file (e.g., VERSION file in the LORIS root directory) or by accessing the LORIS login page footer which typically displays the version number
    Affected if The installed version is >= 15.10 AND <= 27.0.2, OR exactly 28.0.0
  2. Verify help_editor module is enabled
    Check the LORIS configuration file (Config.xml or the modules configuration) to confirm whether the help_editor module is enabled for your installation
    Affected if The help_editor module is listed as enabled in the LORIS configuration
  3. Check for XSS vulnerability in help_editor
    Examine the help_editor module source code (typically in htdocs/help_editor/ or similar path) for the parameter handling logic - look for lack of htmlspecialchars or similar sanitization on user-supplied parameters before output
    Affected if The help_editor PHP code shows direct output of request parameters without proper escaping (e.g., no htmlspecialchars, ENT_QUOTES) on variables like $lang or $section
  4. Check for path traversal vulnerability
    Examine the file download logic in the help_editor module - look for file path parameters that are not validated with realpath() or similar path sanitization before file operations
    Affected if The help_editor file retrieval code accepts a parameter for file path and uses it directly in file operations without validating it stays within an allowed directory

You are affected if your LORIS version falls within 15.10 through 27.0.2 or is exactly 28.0.0 AND the help_editor module is enabled and contains the unsanitized input handling described in the vulnerability.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 27.0.2
Interim mitigation

Upgrade LORIS to version 27.0.3 or 28.0.1 or later to receive the patch for the help_editor module's input sanitization issues.

Recommended fix High confidence

LORIS 27.0.3 or 28.0.1

  1. Backup the current LORIS installation and database before proceeding
  2. Download LORIS version 27.0.3 or 28.0.1 from the official LORIS GitHub repository (github.com/aces/Loris)
  3. Extract the new version to your server
  4. Follow the standard LORIS upgrade procedure: update the codebase and run any required database migrations
  5. Clear any caches and verify the help_editor module functions correctly
  6. Confirm the XSS vulnerability is resolved by testing with the previously vulnerable input vectors
Caveat Patch releases typically have minimal breaking changes; review release notes for any configuration or database changes before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Loris Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-35169 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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