# CVE-2026-75599: HomeBox: Stored XSS via `javascript:` URI in Custom Entity Fields

Status: published. Published: 2026-11-05. Updated: 2026-11-09.

HomeBox is a home inventory and organization system. Prior to 0.27.0, the maybeUrl() utility accepts markdown-style links in entity custom-field values without restricting the URL scheme, so an authenticated user can store a javascript: URI that is rendered as a clickable anchor on an item page. When another authenticated user clicks the link, attacker-controlled JavaScript executes in the victim's HomeBox origin, enabling session theft, account takeover, or data exfiltration. This issue is fixed in version 0.27.0.

## Remediation

- fix: ghcr.io/sysadminsmedia/homebox (docker): GitHub reports patched versions 0.27.0. Check the advisory for the affected release branch. (source: GitHub GHSA-h4x5-6587-jpwp) — https://github.com/sysadminsmedia/homebox/security/advisories/GHSA-h4x5-6587-jpwp
- fix: sysadminsmedia/homebox (docker): GitHub reports patched versions 0.27.0. Check the advisory for the affected release branch. (source: GitHub GHSA-h4x5-6587-jpwp) — https://github.com/sysadminsmedia/homebox/security/advisories/GHSA-h4x5-6587-jpwp

## Affected products and versions

- sysadminsmedia / homebox: < 0.27.0 (affected). Source: CNA: GitHub_M
-  / ghcr.io/sysadminsmedia/homebox (ghcr.io/sysadminsmedia/homebox): < 0.26.2 (affected, GitHub advisory range). Source: GitHub GHSA-h4x5-6587-jpwp
-  / sysadminsmedia/homebox (sysadminsmedia/homebox): < 0.26.2 (affected, GitHub advisory range). Source: GitHub GHSA-h4x5-6587-jpwp

## Severity and prioritization

- CVSS 3.1: 5.4 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N; source: CNA: GitHub_M

- CVSS 3.1: 5.4 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N; source: NVD: security-advisories@github.com

- CISA KEV: No listing in collected sources

- EPSS: 0.17% as of 2026-11-09; percentile 5.81%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-79

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/sysadminsmedia/homebox/security/advisories/GHSA-h4x5-6587-jpwp (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/sysadminsmedia/homebox/commit/d76b1c9b94e91cd74e56ef8a129325d70835471f (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/sysadminsmedia/homebox/releases/tag/v0.27.0 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/sysadminsmedia/homebox/commit/d76b1c9b94e91cd74e56ef8a129325d70835471f (security-advisories@github.com)

- https://github.com/sysadminsmedia/homebox/releases/tag/v0.27.0 (security-advisories@github.com)

- https://github.com/sysadminsmedia/homebox/security/advisories/GHSA-h4x5-6587-jpwp (security-advisories@github.com)

- https://github.com/sysadminsmedia/homebox/security/advisories/GHSA-h4x5-6587-jpwp (GitHub Security Advisories; advisory)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-75599; retrieved 2026-11-09; source updated 2026-11-09

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-75599; retrieved 2026-11-10; source updated 2026-11-09

- GitHub Security Advisories: https://github.com/sysadminsmedia/homebox/security/advisories/GHSA-h4x5-6587-jpwp; retrieved 2026-11-07; source updated 2026-10-17

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-75599; retrieved 2026-11-09; source updated Not reported

Revision: 13d77f0051dbdaaefdfaf6b35a93b849e435e79d13c3f591f96d4ee30b2ba684

Canonical: https://y2.dev/cve/CVE-2026-75599

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.