PT-2026-42577 · Unknown · Concrete Cms

Yonatan Drori · CVE-2026-8435 · Published 2026-05-21 · Updated 2026-05-22

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions Concrete CMS versions 9.0 through 9.4.x

Description Cross Site Request Forgery (CSRF) occurs at the 'concrete/controllers/backend/file' endpoint within the approveVersion() function. CSRF is a flaw that allows an attacker to induce a user to perform actions they did not intend to do.

Recommendations Update to version 9.5.0. As a temporary workaround, restrict access to the approveVersion() function in the 'concrete/controllers/backend/file' endpoint.

Exploit

Fix

CSRF

Weakness Enumeration

CWE-352

CWE-1275

Related Identifiers

CVE-2026-8435

GHSA-44Q4-354F-C826

Affected Products

Concrete Cms

References · 10

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/8xxx/CVE-2026-8435.json · Exploit
• https://osv.dev/vulnerability/CVE-2026-8435 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-8435 · Security Note
• https://osv.dev/vulnerability/GHSA-44q4-354f-c826 · Vendor Advisory
• https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes · Vendor Advisory
• https://github.com/concretecms/concretecms · Note
• https://twitter.com/CVEnew/status/2057783209589358942 · Twitter Post
• https://t.me/cveNotify/164643 · Telegram Post
• https://t.me/CVEtracker/54575 · Telegram Post
• https://twitter.com/infoflowcloud/status/2057785037194412182 · Twitter Post