PT-2026-42580 · Unknown · Concrete Cms

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

Positive Technologies (AI Summary)

CVSS v3.1

6.4

Medium

Base vector

AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

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.

Exploit

Fix

SSRF

Weakness Enumeration

CWE-918

Related Identifiers

CVE-2026-7890

GHSA-GJWQ-9V8P-47W7

Affected Products

Concrete Cms

References · 8

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/7xxx/CVE-2026-7890.json · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-7890 · Security Note
• https://osv.dev/vulnerability/GHSA-gjwq-9v8p-47w7 · Vendor Advisory
• https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2026-7890 · Vendor Advisory
• https://github.com/concretecms/concretecms · Note
• https://twitter.com/CVEnew/status/2057783193999217048 · Twitter Post
• https://t.me/cveNotify/164642 · Telegram Post