CVE-2026-18111Medium· 6.1▾ SunlitConcrete CMS 9 before 9.5.3 was vulnerable to stored cross-site scripting (XSS) in the Feature, Feature Link, Hero Image, and Image blocks and before Concrete 8.5.21 in the feature and Image blocks because the external link URL was insuf…
▾ Sunlit zone — Low / medium · no exploitation signal
impact 33.6 · likelihood 0 · exploitation 0
Need a working PoC? Pro members can cast a request and our team develops one — it lands right here.
Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake.
Exploit-prediction probability, daily snapshots since Sep 19.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
0.3%
0.3% → 0.3%
Last analysed / modified upstream
8.5 → 6.1
high → medium
Concrete CMS 9 before 9.5.3 was vulnerable to stored cross-site scripting (XSS) in the Feature, Feature Link, Hero Image, and Image blocks and before Concrete 8.5.21 in the feature and Image blocks because the external link URL was insufficiently validated by the link filter and was rendered without output escaping. A user with page-editing permissions (such as Add Block combined with Edit Contents on a single page) could store a crafted external link value that broke out of the link markup and injected arbitrary JavaScript. The script executed in the browser session of any user who subsequently viewed, previewed, or edited the affected page, which could lead to session hijacking and escalation of privileges up to full administrative takeover. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 8.5 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks to KhanMarshai for reporting this issue.
concrete_cms < 8.5.21concrete_cms >= 9.0.0, < 9.5.3Upgrade past the affected range:
concrete_cms 9.5.3Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-81926Medium· 6.1Concrete CMS 9.4.0 through 9.5.2 did not escape colliding page paths before rendering them in the location panel's duplicate-path confirmation dialog
CVE-2026-18426Medium· 6.5Concrete CMS 9.0.0 through 9.5.2 did not enforce a block-level edit-permission check on the Express Form block's control-management actions, which relied solely on CSRF token validation
CVE-2026-81927Medium· 5.4Concrete CMS before 9.5.3 contained a stored cross-site scripting vulnerability in SVG file handling
CVE-2026-81925Medium· 6.1Concrete CMS before 9.5.3 improperly neutralized a user-supplied custom date format when rendering conversation messages, resulting in reflected cross-site scripting
CVE-2026-18424High· 7.1Concrete CMS 9.0.0 to 9.5.2 is vulnerable to Server-Side Request Forgery iremote file import via cross-port reuse of a host's validated DNS pin
CVE-2026-18422Medium· 6.5Concrete CMS before 9.5.3 did not enforce a destination-side authorization check and did not validate a CSRF token in the multilingual page assignment backend action (Backend\Page\Multilingual::assign)