Onyx: Cross-user OAuth-token leak via /api/mcp/servers* for per-user MCP servers

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-71424
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-17 22:17:26 UTC
Updated2026-08-17 22:17:26 UTC
DescriptionOnyx is an open-source AI platform. Prior to 3.1.10, 3.2.14, and 4.0.0, Onyx's GET /api/mcp/servers and GET /api/mcp/servers/persona/{persona_id} endpoints expose another user's OAuth Authorization header because OnyxTokenStorage.set_tokens and OnyxTokenStorage.set_client_info in backend/onyx/server/features/mcp/api.py copy per-user tokens into a shared admin MCPConnectionConfig row and _db_mcp_server_to_api_mcp_server returns that row through auth_template.headers to any BASIC_ACCESS user. This issue is fixed in versions 3.1.10, 3.2.14, and 4.0.0.

Risk And Classification

Primary CVSS: v3.1 9.6 CRITICAL from [email protected]

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

Problem Types: CWE-200 | CWE-863 | CWE-200 CWE-200: Exposure of Sensitive Information to an Unauthorized Actor | CWE-863 CWE-863: Incorrect Authorization

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary9.6CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
3.1CNADECLARED9.6CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

CVSS v3.1 Breakdown

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

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Onyx-dot-app Onyx affected < 3.1.10 Not specified
CNA Onyx-dot-app Onyx affected >= 3.2.0, < 3.2.14 Not specified
CNA Onyx-dot-app Onyx affected >= 3.3.0-beta.0, < 4.0.0 Not specified

References

ReferenceSourceLinkTags
github.com/onyx-dot-app/onyx/security/advisories/GHSA-q62f-rv3h-f822 [email protected] github.com
github.com/onyx-dot-app/onyx/pull/11238 [email protected] github.com
github.com/onyx-dot-app/onyx/releases/tag/v4.0.0 [email protected] github.com
github.com/onyx-dot-app/onyx/commit/3f3d79d1a7722fdc84a1c61c8aa830d89001... [email protected] github.com
github.com/onyx-dot-app/onyx/pull/11242 [email protected] github.com
github.com/onyx-dot-app/onyx/commit/4001cedd0a8968723bfe95dd188914ed5677... [email protected] github.com
github.com/onyx-dot-app/onyx/commit/b103937888fd5008067c2bb6eb6e54245763... [email protected] github.com
github.com/onyx-dot-app/onyx/pull/11243 [email protected] github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report