CVE-2026-48976
HomeBox: Cross-Tenant IDOR in Notifier Update Leaks Shoutrrr Credentials and Allows Webhook Hijack
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
8.1
HomeBox: Cross-Tenant IDOR in Notifier Update Leaks Shoutrrr Credentials and Allows Webhook Hijack
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.
- Record
CVE-2026-48976- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-522, CWE-639
- Updated
- 2026-11-02
EUVDEUVD-2026-84033
8.1
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.
- Record
EUVD-2026-84033- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
NVD
8.1
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.
- Record
CVE-2026-48976- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-522, CWE-639
- Updated
- 2026-11-02
OSV
8.1
HomeBox: Cross-Tenant IDOR in Notifier Update Leaks Shoutrrr Credentials and Allows Webhook Hijack
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.
- Record
CVE-2026-48976- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-522, CWE-639
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-48976 is a high vulnerability (CVSS 8.1) in Sysadminsmedia Homebox, published September 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.45%, the 39th percentile. No source names a fixed version.
References
github.com/sysadminsmedia/homebox/security/advisories/GHSA-mc8h-5c5v-37p7
github.com/sysadminsmedia/homebox/commit/ed3216a80998dfd81d4418700696244144883160
github.com/sysadminsmedia/homebox/releases/tag/v0.26.0
github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48976.json
nvd.nist.gov/vuln/detail/CVE-2026-48976