GHSA-R42C-3RR2-JRFP
Vulnerability from github – Published: 2026-05-21 21:30 – Updated: 2026-05-26 21:31Concrete CMS 9.5.0 and below does not validate a CSRF token before processing requests to /dashboard/extend/install/download/. The download() method in concrete/controllers/single_page/dashboard/extend/install.php checks only the canInstallPackages() permission before fetching a remote marketplace package and writing it to the server's DIR_PACKAGES directory. Because the endpoint is a state-changing GET route with no token enforcement, an attacker who can cause an authenticated administrator to visit a crafted page can force an arbitrary marketplace package to be downloaded. In order to be vulnerable, the victim must be passing canInstallPackages() and the site must be connected to the Concrete marketplace. 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.
{
"affected": [],
"aliases": [
"CVE-2026-8140"
],
"database_specific": {
"cwe_ids": [
"CWE-352"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-21T21:16:33Z",
"severity": "HIGH"
},
"details": "Concrete CMS 9.5.0 and below does not validate a CSRF token before processing requests to /dashboard/extend/install/download/\u003cremoteId\u003e. The download() method in concrete/controllers/single_page/dashboard/extend/install.php checks only the canInstallPackages() permission before fetching a remote marketplace package and writing it to the server\u0027s DIR_PACKAGES directory. Because the endpoint is a state-changing GET route with no token enforcement, an attacker who can cause an authenticated administrator to visit a crafted page can force an arbitrary marketplace package to be downloaded. In order to be vulnerable, the victim must be passing canInstallPackages() and the site must be connected to the Concrete marketplace.\u00a0The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of\u00a07.5 with vector\u00a0CVSS: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\u00a0 https://github.com/maru1009 \u00a0for reporting.",
"id": "GHSA-r42c-3rr2-jrfp",
"modified": "2026-05-26T21:31:37Z",
"published": "2026-05-21T21:30:37Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-8140"
},
{
"type": "WEB",
"url": "https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
},
{
"score": "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/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",
"type": "CVSS_V4"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.