CVE-2026-63178Public exploitNetwork attack vectorHinoki check available

Cross-group document disclosure via unscoped group writes

Published Aug 17, 2026 · Updated Aug 18, 2026

Authorization bypass in Onyx Enterprise Edition before 4.3.0 allows remote authenticated users to read other groups' documents via user-group APIs. In ee/onyx/server/user_group/api.py, the PATCH and add-users routes check only current_curator_or_admin_user, then call update_user_group and add_users_to_user_group in ee/onyx/db/user_group.py without verifying that the supplied user_group_id belongs to one of the caller's curated groups. Curator access is required, but no admin role, user interaction, or special setup beyond Enterprise Edition is needed; a curator can self-add to another group and inherit that group's OpenSearch-filtered document access, while also rewriting memberships or cc-pair bindings for unauthorized groups.

CVSS severity6.5
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Authorization bypass in Onyx Enterprise Edition before 4.3.0 allows remote authenticated users to read other groups' documents via user-group APIs. In ee/onyx/server/user_group/api.py, the PATCH and add-users routes check only current_curator_or_admin_user, then call update_user_group and add_users_to_user_group in ee/onyx/db/user_group.py without verifying that the supplied user_group_id belongs to one of the caller's curated groups. Curator access is required, but no admin role, user interaction, or special setup beyond Enterprise Edition is needed; a curator can self-add to another group and inherit that group's OpenSearch-filtered document access, while also rewriting memberships or cc-pair bindings for unauthorized groups.

The record

CVE
CVE-2026-63178
Published
Aug 17, 2026
Updated
Aug 18, 2026
Vendor
Onyx
Product
Onyx
Classifications
CWE-639, T1098
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Onyx · Onyxversion=< 4.3.0

Published CVSS scores

6.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-639Authorization Bypass Through User-Controlled Key
T1098Account Manipulation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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