CVE-2026-18424

Concrete 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. When multiple remote URLs share the same host, only the first `ValidatedRemoteUrl` is retained and reused for every later URL with that host. A low-privileged authenticated user permitted to import files could therefore supply a DNS-rebinding host that resolved to a public address during validation and to a private or loopback address during the unpinned download, causing the server to fetch internal-only resources such as loopback services, internal admin panels, or cloud metadata endpoints and to save the responses into the file manager. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.1 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N. Thanks Ahmad Wicaksono (sonix03) for reporting.

• CWE-918

• https://documentation.concretecms.org/developers/introduction/version-history/953-release-notesBroken Link

Published

Sep 15, 2026

Last Modified

Sep 21, 2026

Status

Analyzed

• One Click Account Takeover in GranolaHow a notification link broke out of Electron and led to a one-click account takeover.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2026-18412OpenCart extensions are uploaded as zip files with .ocmod.zi…9.1
• CVE-2026-1842HyperCloud versions 2.3.5 through 2.6.8 improperly allowed r…6.2
• CVE-2026-18420Improper input validation in the Time Series Visual Builder …8.8
• CVE-2026-18421Concrete CMS 9 through 9.5.2 does not perform an authorizati…2.1
• CVE-2026-18422Concrete CMS before 9.5.3 did not enforce a destination-side…6.5
• CVE-2026-18423Concrete CMS 9.0.0 through 9.5.2 is vulnerable to Insecure d…7.1
• CVE-2026-18425Concrete CMS 9 before 9.5.3 authorized the dashboard sitemap…2.7
• CVE-2026-18426Concrete CMS 9.0.0 through 9.5.2 did not enforce a block-lev…6.5
• CVE-2026-18427@fastify/static before version 10.1.3 contains an incomplete…7.5
• CVE-2026-18428A SQL query validation bypass in the Flint extension query h…8.8
• CVE-2026-1843The Super Page Cache plugin for WordPress is vulnerable to S…7.2
• CVE-2026-18430HumHub 1.18.4 contains a stored cross-site scripting vulnera…7.2