CVE-2026-7890: Concrete CMS 9.5.0 is vulnerable to SSRF via RSS Displayer Block

Published May 21, 2026
·
Updated

In Concrete CMS 9.5.0 and below, the RSS Displayer block accepts a feed URL from any page editor and fetches it server-side without validation enabling redirect-to-internal bypasses.  The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.1 with a vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:L/VA:N/SC:L/SI:N/SA:N.

Affected Software

2 affected components
Concrete CMS Concrete CMS<=9.5.0
ConcreteCMS Concrete CMS<9.5.1

Event History

May 21, 2026
CVE Published
via MITRE·09:43 PM
Data Sourced
via MITRE·09:43 PM
DescriptionWeakness
Data Sourced
via NVD·10:16 PM
DescriptionSeverityWeaknessAffected Software
Jun 23, 58372
Event
via FIRST·06:22 AM

Frequently Asked Questions

1

What is the severity of CVE-2026-7890?

The severity of CVE-2026-7890 is rated as low with a CVSS score of 2.1.

2

What type of vulnerability is CVE-2026-7890?

CVE-2026-7890 is classified as a Server-Side Request Forgery (SSRF) vulnerability.

3

How do I fix CVE-2026-7890?

To fix CVE-2026-7890, ensure you validate all feed URLs provided in the RSS Displayer block before server-side fetching.

4

Which versions of Concrete CMS are affected by CVE-2026-7890?

CVE-2026-7890 affects Concrete CMS version 9.5.0 and below.

5

What potential impact does CVE-2026-7890 have?

CVE-2026-7890 can lead to redirect-to-internal bypasses, compromising internal resources.

Contact

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