CVE-2026-48976 HomeBox: Cross-Tenant IDOR in Notifier Update Leaks Shoutrrr Credentials and Allows Webhook Hijack
Authenticated users can access or modify other tenants' notifiers, leaking credentials and hijacking webhooks in HomeBox.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-48976?
CVE-2026-48976 is a high-severity missing authorization vulnerability in sysadminsmedia homebox, published on 21 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
HomeBox is a home inventory and organization system. Prior to 0.26.0, NotifierRepository.Update in backend/internal/data/repo/repo_notifier.go updates a notifier through UpdateOneID(id) without requiring the record's user ID to match the authenticated user. An authenticated user who supplies another tenant's notifier UUID to PUT /v1/notifiers/{id} can read the returned stored url, which may contain plaintext Shoutrrr credentials for Slack, SMTP, Telegram, Pushover, or Discord, and can replace the URL to redirect the victim's notifications to an attacker-controlled webhook. This issue is fixed in version 0.26.0.
Which versions are affected by CVE-2026-48976?
How do I fix CVE-2026-48976?
No fix has been published for CVE-2026-48976 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-48976 being exploited?
There is no known exploitation of CVE-2026-48976 in the wild and no public exploit code.
Sources
Also known as GHSA-mc8h-5c5v-37p7.