CVE-2026-8421
- Source
- https://cve.org/CVERecord?id=CVE-2026-8421
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-8421.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-8421
- Aliases
- Published
- 2026-05-21T20:25:11.868Z
- Modified
- 2026-07-15T01:49:18.986684536Z
- Severity
-
- 7.5 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CVSS Calculator
- Summary
- Concrete CMS 9.5.0 and below is vulnerable to CSRF on install_package() with conditional token bypass leading to RCE
- Details
-
Concrete CMS 9.5.0 and below contains a CSRF vulnerability in the installpackage() method of concrete/controllers/singlepage/dashboard/extend/install.php. An attacker who can cause an authenticated administrator to visit a crafted page, and who has placed or caused a package to be present under DIR_PACKAGES/<handle>/, can force the installation of that package without any CSRF protection. Package installation executes the package controller's install() method as the web server user, enabling remote code execution. In order to be vulnerable, the victim must be passing canInstallPackages. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 7.5 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks https://github.com/maru1009 for reporting.
- Database specific
{ "cwe_ids": [ "CWE-352" ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/8xxx/CVE-2026-8421.json", "cna_assigner": "ConcreteCMS" }- References
Affected packages
Git / github.com/concretecms/concretecms
Affected ranges
- Type
- GIT
- Repo
- https://github.com/concretecms/concretecms
- Events
-
Introduced0 Unknown introduced commit / All previous commits are affectedFixed
- Database specific
{ "cpe": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*", "extracted_events": [ { "introduced": "5.0" }, { "last_affected": "9.5.0" }, { "introduced": "0" }, { "fixed": "9.5.1" } ], "source": [ "AFFECTED_FIELD", "CPE_RANGE" ] }