LorisApplication · Mcgill

CVE-2026-34392

HIGH · 7.5 CVSS v3.1 Published 2026-04-08
Fix available
A fix is available. Upgrade to 27.0.3 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click Patch available

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 20.0.0 to before 27.0.3 and 28.0.1, a bug in the static file router can allow an attacker to traverse outside of the intended directory, allowing unintended files to be downloaded through the static, css, and js endpoints. 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

A detailed technical summary for this CVE is being prepared.

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:>= 20.0.0, < 27.0.3= 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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

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

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 27.0.3 or later
Fixed in 27.0.3
Vendor patch github.com →
Recommended fix High confidence

27.0.3 or 28.0.1 (or later respective branch)

  1. 1. Identify your current Loris version by checking the codebase or admin interface
  2. 2. If running version 20.0.0 through 27.0.2, plan upgrade to version 27.0.3 or later
  3. 3. If running version 28.0.0, plan upgrade to version 28.0.1 or later
  4. 4. Review the release notes for your target version at https://github.com/aces/Loris/releases
  5. 5. Backup your database and Loris codebase before upgrading
  6. 6. Follow the standard Loris upgrade procedure documented at https://loris.readthedocs.io/
  7. 7. After upgrade, verify the static file endpoints (static, css, js) are functioning correctly
Caveat Review release notes for your target version; point releases typically have minimal breaking changes but verify any database migrations or configuration changes

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

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,950. Get the upgrade done

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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-2026-34392 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data