Vulnerability · Published Apr 17, 2026 · Assigned by GitHub_M

CVE-2026-40196HomeBox has Unauthorized API Access via Retained defaultGroup ID After Group Access Revocation

High 8.1

In plain English

A high-severity security flaw in homebox from sysadminsmedia. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities).

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.2%top 83.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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ID remained permanently assigned to a user after being invited to a group, even after their access to that group was revoked.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 products (as reported)

Vendor	Product	Versions
sysadminsmedia	homebox	< 0.25.0

Weakness: CWE-708 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

References

https://github.com/sysadminsmedia/homebox/security/advisories/GHSA-6pvm-v73p-p6m9 x_refsource_CONFIRM
https://github.com/sysadminsmedia/homebox/releases/tag/v0.25.0 x_refsource_MISC