PT-2026-42580 · Unknown · Concrete Cms

0X4C616E · Published 2026-05-21 · Updated 2026-05-22 · CVE-2026-7890

Positive Technologies (AI Summary)

CVSS v4.0

2.1

Low

Base vector

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

Name of the Vulnerable Software and Affected Versions Concrete CMS versions 9.5.0 and earlier

Description The RSS Displayer block accepts a feed URL from page editors and fetches it server-side without proper validation. This lack of validation allows for redirect-to-internal bypasses, where an attacker can potentially redirect requests to internal resources.

Recommendations Update to a version later than 9.5.0. As a temporary workaround, restrict access to the RSS Displayer block for untrusted page editors.

Fix

SSRF

Weakness Enumeration

CWE-918

Related Identifiers

CVE-2026-7890

Affected Products

Concrete Cms

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-7890 · Security Note
• https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes · Note
• https://t.me/cveNotify/164642 · Telegram Post
• https://twitter.com/CVEnew/status/2057783193999217048 · Twitter Post