Medium severity · published Aug 17, 2026
CVE-2026-63178
Onyx Curator-scope IDOR: any curator can modify membership of arbitrary user groups via unscoped PATCH /manage/admin/user-group/{id} and /add-users leading to cross-group document disclosure
6.5
CVSS
0.5%
EPSS
No
On KEV
Description
Onyx is an open-source AI platform. Prior to 4.3.0, Onyx Enterprise Edition's PATCH /manage/admin/user-group/{user_group_id} and POST /manage/admin/user-group/{user_group_id}/add-users endpoints in ee/onyx/server/user_group/api.py call update_user_group and add_users_to_user_group in ee/onyx/db/user_group.py without enforcing _validate_curator_can_modify_group, allowing a curator to add accounts to arbitrary groups and obtain document access through get_acl_for_user and the OpenSearch access_control_list filter. This issue is fixed in version 4.3.0.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 44% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ON
onyx · onyx-dot-app
< 4.3.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-63178
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-63178
github.com
https://github.com/onyx-dot-app/onyx/commit/46e19cc2750fed659488cb12a1f171016ba5a099
github.com
https://github.com/onyx-dot-app/onyx/commit/b9e1c6894be3c237283f4b5fd4eb0af935b40664
github.com
https://github.com/onyx-dot-app/onyx/pull/12525
github.com
https://github.com/onyx-dot-app/onyx/pull/12549
github.com
https://github.com/onyx-dot-app/onyx/releases/tag/v4.3.0
github.com
https://github.com/onyx-dot-app/onyx/security/advisories/GHSA-7f48-vgpj-h95m
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