CVE-2026-42277

Onyx: IDOR in /chat/file/{file_id} allows any authenticated user to download other users files

Published May 8, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed

Description

Onyx is an open-source AI platform. Prior to versions 3.0.9, 3.1.6, and 3.2.6, the GET /chat/file/{file_id} endpoint allows any authenticated user to download any other user's uploaded files by providing the file UUID. The endpoint verifies the caller is authenticated but never checks that the file belongs to them. An attacker who knows or obtains a file UUID can access confidential documents, chat attachments, and other files uploaded by any user in the system. This issue has been patched in versions 3.0.9, 3.1.6, and 3.2.6.

Analysis

Technical impact

The vulnerability allows any authenticated user to download any other user’s uploaded files by requesting the file UUID through the GET /chat/file/{file_id} endpoint. The request only verifies the caller is authenticated but never checks that the file belongs to the caller, enabling a classic IDOR that can expose sensitive documents and chat attachments.

Affected Systems

The issue affects the Onyx open‑source AI platform produced by onyx-dot-app. Versions prior to 3.0.9, 3.1.6 and 3.2.6 are vulnerable, including all 3.0.x releases up to 3.0.8, all 3.1.x releases up to 3.1.5 and all 3.2.x releases up to 3.2.5.

Risk and Exploitability

The CVSS score of 6.5 indicates moderate severity. EPSS data is not available and the vulnerability is not listed in the CISA KEV catalog, but the lack of an ownership check means an authenticated user who knows or discovers a file UUID can download any file. This makes exploitation straightforward in environments where file identifiers are shared or guessable, allowing attackers to read confidential data.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

onyx-dot-app

onyx

affected

Version	Status	Constraints
`< 3.0.9`	affected	—
`>= 3.1.0, < 3.1.6`	affected	—
`>= 3.2.0, < 3.2.6`	affected	—

Configuration 1 [-]

OR	cpe:2.3:a:onyx:onyx::::::::
	cpe:2.3:a:onyx:onyx::::::::
	cpe:2.3:a:onyx:onyx::::::::

No data.

Vendor Product Versions

Onyx

Version	Status	Scheme	Platform
`[0,3.0.9)`	affected	semver	—
`[3.1.0,3.1.6)`	affected	semver	—
`[3.2.0,3.2.6)`	affected	semver	—

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Update to Onyx 3.0.9, 3.1.6, 3.2.6 or later, which patch the ownership validation
If an upgrade is not possible, restrict the /chat/file endpoint so only the original uploader can download the file
Monitor authentication sessions for unusual requests to /chat/file with unfamiliar file IDs

Generated by OpenCVE AI on May 8, 2026 at 06:22 UTC.

Tracking

Advisories

No advisories available

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.201% probability within 30 days)

Exploitation poc

Automatable no

Technical Impact partial

References

Link	Providers
https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-vg3h-35f7-7w6r

History

May 12, 2026 2:00 PM Affected versions updated View changes

Type	Values Removed	Values Added
CPEs		cpe:2.3:a:onyx:onyx::::::::

May 10, 2026 9:45 PM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Onyx Onyx onyx
Vendors & Products		Onyx Onyx onyx

May 8, 2026 10:15 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

May 8, 2026 5:00 AM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		Onyx is an open-source AI platform. Prior to versions 3.0.9, 3.1.6, and 3.2.6, the GET /chat/file/{file_id} endpoint allows any authenticated user to download any other user's uploaded files by providing the file UUID. The endpoint verifies the caller is authenticated but never checks that the file belongs to them. An attacker who knows or obtains a file UUID can access confidential documents, chat attachments, and other files uploaded by any user in the system. This issue has been patched in versions 3.0.9, 3.1.6, and 3.2.6.
Title		Onyx: IDOR in /chat/file/{file_id} allows any authenticated user to download other users files
Weaknesses		CWE-639
References		https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-vg3h-35f7-7w6r
Metrics		cvssV3_1 `{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N'}`