VulnerabilityPublished 8 Apr 2026

CVE-2026-35446: aces Loris · Exposed Files or Directories

Affects aces LorisSource CVE Database V5

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Not known to be exploited · CVSS 7.7 High : upgrade to 28.0.1 or 27.0.3 soon.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 3.1 base score

7.7High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 28.0.1, 27.0.3

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Changed
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 8 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Loris to 28.0.1 or 27.0.3; aces/Loris to 27.0.3.

Affected software

Product	Affected	Fixed in
acesLoris	Affected >=28.0.0 <28.0.1	Fixed in 28.0.1
acesLoris	Affected >=24.0.0 <27.0.3	Fixed in 27.0.3
GitHubaces/Loris`pkg:github/aces/Loris`Other threats	Affected >=24.0.0 <27.0.3 =28.0.0	Fixed in 27.0.3

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available in LORIS versions 27.0.3 and 28.0.1. Users should upgrade to one of these versions or later to remediate this vulnerability. Since this is a self-hosted application, administrators must apply the update themselves. Patch status is confirmed by the vendor's versioning information. No additional mitigation guidance is provided or required beyond applying the official fix.

Description

LORIS (Longitudinal Online Research and Imaging System) is a self-hosted web application that provides data- and project-management for neuroimaging research. From 24.0.0 to before 27.0.3 and 28.0.1, an incorrect order of operations in the FilesDownloadHandler could result in an attacker escaping the intended download directories. This vulnerability is fixed in 27.0.3 and 28.0.1.

Impact

An attacker with low privileges can exploit this vulnerability remotely over the network without user interaction to access sensitive files or directories outside the intended download directories. This results in a confidentiality breach but does not affect integrity or availability. The scope of the impact is changed, meaning the vulnerability affects resources beyond the initially intended security boundary.

Summary

LORIS is a self-hosted web application used for neuroimaging research data and project management. In affected versions, a logic error in the FilesDownloadHandler component permits directory traversal or similar unauthorized access, enabling external parties to access files or directories outside the intended download scope. This is classified under CWE-552, which concerns files or directories accessible to external parties due to improper access control. The vulnerability has a CVSS 3.1 base score of 7.7, indicating high severity, with network attack vector, low attack complexity, requiring low privileges but no user interaction, and impacts confidentiality with a scope change. The issue is resolved in LORIS versions 27.0.3 and 28.0.1.

CWE-552Files or Directories Accessible to External Parties (opens in a new tab)
Base weaknessOWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product makes files or directories accessible to unauthorized actors, even though they should not be.
Implementation · System Configuration · Operation
When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to disable public access.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.5.1 (opens in a new tab)
V12.4.1 (opens in a new tab)
V8.3.8 (opens in a new tab)
Attack patterns
Collect Data from Common Resource Locations (opens in a new tab)
Probe System Files (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/aces/Loris/security/advisories/GHSA-47jj-7xfg-8759 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 8 Apr 2026, 20:50 UTC

WeaknessesCWE-552

Technical details

References

Community reviews

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