CVE-2026-40196: HomeBox has Unauthorized API Access via Retained defaultGroup ID After Group Access Revocation
HomeBox is a home inventory and organization system. Versions prior to 0.25.0 contain a vulnerability where the defaultGroup ID remained permanently assigned to a user after being invited to a group, even after their access to that group was revoked. While the web interface correctly enforced the access revocation and prevented the user from viewing or modifying the group's contents, the API did not. Because the original group ID persisted as the user's defaultGroup, and this value was not properly validated when the X-Tenant header was omitted, the user could still perform full CRUD operations on the group's collections through the API, bypassing the intended access controls. This issue has been fixed in version 0.25.0.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
HomeBoxto a version that resolves this vulnerability.Fixed in 0.25.0
Event History
Frequently Asked Questions
What is the severity of CVE-2026-40196?
CVE-2026-40196 has been rated as a medium severity vulnerability due to the risk of unauthorized access to API functionalities.
How do I fix CVE-2026-40196?
To fix CVE-2026-40196, update HomeBox to version 0.25.0 or later where the vulnerability has been addressed.
What is the impact of CVE-2026-40196?
The impact of CVE-2026-40196 allows unauthorized users to retain access to the defaultGroup ID after group access has been revoked.
Who is affected by CVE-2026-40196?
Users of HomeBox versions prior to 0.25.0 are affected by CVE-2026-40196.
Is there a workaround for CVE-2026-40196?
There are no known effective workarounds for CVE-2026-40196; the best solution is to upgrade to the latest version.