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
Attackers can execute arbitrary scripts in the site origin via unescaped RSS feed titles, potentially compromising visitor accounts including administrators.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-68528?
CVE-2026-68528 is a medium-severity cross-site scripting vulnerability in Concrete CMS, published on 11 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-68528?
How do I fix CVE-2026-68528?
No fix has been published for CVE-2026-68528 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-68528 being exploited?
There is no known exploitation of CVE-2026-68528 in the wild and no public exploit code.
Sources
Also known as GHSA-rq97-c8jm-449q.