CVE-2026-35165 | LORIS has incorrect access checks in document_repository

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.

Published: 2026-04-08 Last update: 2026-04-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-35165 is rated Low Risk (28/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.03%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-35165

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-09 0.03%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-35165

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
2.8 3.4 [email protected]
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 3.6 [email protected]

Weakness enumeration for CVE-2026-35165

Affected software / configurations for CVE-2026-35165

Vendor Product Version Raw CPE
mcgill loris >= 21.0.0, <= 27.0.2 cpe:2.3:a:mcgill:loris:*:*:*:*:*:*:*:*
mcgill loris 28.0.0 cpe:2.3:a:mcgill:loris:28.0.0:*:*:*:*:*:*:*

References for CVE-2026-35165

cvelogic Threat Intelligence