CVE-2026-7890: 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…

PriorityP434medium6.4CVSS 3.1

AVNACLPRLUINSCCLILAN

EPSS

0.15%

4.8th percentile

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

3 ranges

Vendor	Product	Version range	Fixed in
concrete5	concrete5	>= 0 < 9.5.1	9.5.1
concrete_cms	concrete_cms	5.0 – 9.5.0	—
concretecms	concrete_cms	< 9.5.1	9.5.1

CVSS provenance

nvdv3.16.4MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

nvdv4.02.1LOWCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:L/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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