Concrete CMS RSS Displayer block below version 9.5.3 rendered remote feed item titles without HTML escaping, resulting in stored cross-site scripting. (CVE-2026-68528)
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.
AI Analysis
Technical Summary
The RSS Displayer block in Concrete CMS versions prior to 9.5.3 improperly renders remote feed item titles without escaping HTML, leading to stored cross-site scripting (CWE-79). This allows an attacker who can control a title in a syndicated feed to inject malicious scripts that execute in the origin context of the site for any visitor of the affected page. The vulnerability has a CVSS v4.0 base score of 6.0, indicating medium severity, with network attack vector, high attack complexity, and requiring user interaction.
Potential Impact
Successful exploitation enables script execution in the context of the affected site for any visitor, including administrators, potentially leading to session hijacking, defacement, or other malicious actions within the site origin. The attacker does not need an account on the site but must control a syndicated feed title.
Mitigation Recommendations
Upgrade Concrete CMS to version 9.5.3 or later where this vulnerability is fixed. No other mitigation or temporary workaround is indicated. Patch status is confirmed by the vendor advisory stating fixed in 9.5.3.
Concrete CMS RSS Displayer block below version 9.5.3 rendered remote feed item titles without HTML escaping, resulting in stored cross-site scripting. (CVE-2026-68528)
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.
CVSS v4.0
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The RSS Displayer block in Concrete CMS versions prior to 9.5.3 improperly renders remote feed item titles without escaping HTML, leading to stored cross-site scripting (CWE-79). This allows an attacker who can control a title in a syndicated feed to inject malicious scripts that execute in the origin context of the site for any visitor of the affected page. The vulnerability has a CVSS v4.0 base score of 6.0, indicating medium severity, with network attack vector, high attack complexity, and requiring user interaction.
Potential Impact
Successful exploitation enables script execution in the context of the affected site for any visitor, including administrators, potentially leading to session hijacking, defacement, or other malicious actions within the site origin. The attacker does not need an account on the site but must control a syndicated feed title.
Mitigation Recommendations
Upgrade Concrete CMS to version 9.5.3 or later where this vulnerability is fixed. No other mitigation or temporary workaround is indicated. Patch status is confirmed by the vendor advisory stating fixed in 9.5.3.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-rq97-c8jm-449q
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-68528"]
- Database Specific Severity
- MODERATE
- Cvss Version
- 4.0
Threat ID: 6aa47eba55bf5e2cf58579ae
Added to database: 09/11/2026, 22:20:42 UTC
Last enriched: 09/11/2026, 22:49:07 UTC
Last updated: 09/12/2026, 01:03:18 UTC
Views: 4
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