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Cotton Cloud security vulnerabilities

mySites.guru tracks 2 vulnerabilities in com_cotton. Every connected Joomla site is checked against them on each audit, and flagged if it runs an affected version.

What we check for

Cotton Cloud (com_cotton) below 2.0.2 - Unauthenticated Access to the Entire File Store (CVE-2026-67283)

Cotton Cloud is a database backed cloud file store for Joomla, shipped as the pkg_cotton package (com_cotton file manager, com_shuttle terminal and MCP server, com_weaver editor, mod_cotton, plg_editors-xtd_cotton, LibCotton). In every release up to and including 2.0.1 the login check sits in the view layer, so it only runs when the component renders a page. The task endpoints never construct the view, and their only gate is a CSRF token check, which Joomla happily issues to an anonymous visitor. A visitor with no account and no session can therefore read, overwrite, delete and re-assign permissions on every file held in the store, regardless of who owns it, and can create new files inside another user's folder. Because the component serves stored files with a Content-Type derived from the file extension, an uploaded .html file is returned as text/html and executes on the site's own origin, which makes stored cross site scripting a downstream consequence. This is not remote code execution: files live in a database column, never on a web served path, so a stored .php file is echoed as bytes rather than executed. CVE-2026-67283, CVSS 4.0 6.9 Medium (AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N), CWE-284 improper access control, published 12 August 2026 by the Joomla CNA and reported by Phil Taylor of mySites.guru. Update to Cotton Cloud 2.0.2 or later. Interim mitigation: unpublish any Cotton menu items and unpublish the Cotton and Shuttle components, since unpublishing the menu item alone does not close the task endpoints.

Affected versions: < 2.0.2

Full advisory: www.cve.org

Cotton Cloud (com_cotton) 2.0.2 - Authenticated Access to Every Other User's Files (CVE-2026-67284)

Cotton Cloud 2.0.2 fixed the unauthenticated access covered by CVE-2026-67283 but left the underlying authorisation flaw in place. The by-id database accessors fetch files and folders by their numeric id with no check that the id belongs to the caller, so any authenticated user can read, overwrite, delete and re-assign permissions on files owned by any other user. On a site with open user registration, which is the normal setup for a file store, a free account is enough. The component also sets the response content type from the file extension, so an attacker can plant an HTML file that serves script from the site's own origin. CVSS 4.0 5.3 MEDIUM (AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N), CWE-284. Update to Cotton Cloud 2.0.3 or later. Reported by Phil Taylor of mySites.guru.

Affected versions: ≥ 2.0.2 and < 2.0.3

Full advisory: our disclosure post

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CVE identifiers: CVE-2026-67283, CVE-2026-67284. Rules current as of 13 September 2026.