LorisApplication · Mcgill

CVE-2026-35165

MEDIUM · 6.5 CVSS v3.1 Published 2026-04-08
Fix available
A fix is available. Upgrade to after 27.0.2 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable 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 21.0.0 to before 27.0.3 and 28.0.1, while the document_repository frontend was restricting file access, the backend endpoint was not correctly verifying access permissions. A user could theoretically download a file that they should not have access to, if they know or can brute force the filename. 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
How this class of weakness works · CWE-639

The application uses a user-supplied identifier to look up a record without checking that the requester actually owns it, so changing the identifier in a request returns someone else's data. This is the classic insecure-direct-object-reference — the change-the-ID-in-the-URL bug. Remediation is authorizing every object access against the acting user, not merely confirming they are logged in.

General guidance for the authorization bypass (idor) class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

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:>= 21.0.0, <= 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
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/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 a release after 27.0.2
Vendor patch github.com →
Recommended fix High confidence

27.0.3 (for 27.x line) or 28.0.1 (for 28.x line)

  1. Backup the current Loris installation and database before upgrading
  2. Determine your current major version (27.x or 28.x)
  3. If running 27.x: upgrade to version 27.0.3 or later
  4. If running 28.x: upgrade to version 28.0.1 or later
  5. After upgrade, verify the document_repository module now correctly enforces access controls on the backend endpoint
  6. Test that unauthorized users can no longer download files they shouldn't have access to
Caveat Minor version upgrades within the same major version typically have minimal breaking changes; consult release notes when upgrading between major version lines

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

We can identify the exact fixed release, upgrade, and verify it in staging — typical engagement from $1,600. Get the upgrade done

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-35165 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2026-35165 in production — separate from our analysis above.

No notes yet

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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