Affected versions: ≥ 2.0.2 and < 2.0.3
Full advisory: our disclosure post
CVE-2026-67284MediumCVSS 5.3CVE published 12 August 2026
Cotton Cloud (com_cotton) 2.0.2 - Authenticated Access to Every Other User's Files
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.
Is my site affected?
- Affected
- Cotton Cloud from 2.0.2 up to but not including 2.0.3
- Fixed in
- 2.0.3
- What to do
- Update Cotton Cloud to 2.0.3 or later.
How CVE-2026-67284 is scored
The base metrics as Joomla CNA published them, and what each one means for a site running an affected version. Threat and environmental metrics are left out: they describe a moment or a particular install rather than the flaw.
5.3 Medium
CVSS 4.0, scored by Joomla CNACVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:NHow it is reached
- AV:N Attack vector
- Network. Reachable across the internet
- AC:L Attack complexity
- Low. Nothing to work around, it just works
- AT:N Attack requirements
- None. Works against any affected install
- PR:L Privileges required
- Low. Any logged-in account will do
- UI:N User interaction
- None. Nobody has to be tricked into anything
What it does to the site
- VC:L Confidentiality
- Low. Some data can be read
- VI:L Integrity
- Low. Some data can be altered
- VA:N Availability
- None. The site stays up
What it does beyond the site
- SC:N Confidentiality
- None. Other systems keep their data
- SI:N Integrity
- None. Other systems keep their integrity
- SA:N Availability
- None. Other systems stay up
Timeline
- 12 August 2026CVE-2026-67284 record published by its CNA
- 12 August 2026We published: Cotton Cloud Patched the Login, Then the Data
Rule details
Our disclosure post
Other vulnerabilities in Cotton Cloud
Updating for CVE-2026-67284 alone can leave a site on a release another rule still matches. These are the other flaws we check for in the same extension.
References
- CVE-2026-67284 on cve.org (the official CVE record)
- CVE-2026-67284 in the NIST National Vulnerability Database
- Cotton Cloud Patched the Login, Then the Data
CVE-2026-67284 questions
Which versions are affected by CVE-2026-67284?
CVE-2026-67284 affects Cotton Cloud from 2.0.2 up to but not including 2.0.3. The fix is in 2.0.3.
How do I fix CVE-2026-67284?
Update Cotton Cloud to 2.0.3 or later. Then confirm the installed version on the Joomla administrator's Extensions: Manage screen.
How severe is CVE-2026-67284?
Joomla CNA scores it 5.3 (Medium) under CVSS 4.0. In plain terms: reachable across the internet, any logged-in account will do and nobody has to be tricked into anything.
Running an affected version on a site you manage?
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This check is part of the mySites.guru Joomla vulnerability scanner, which reads every installed extension's version on each audit. Browse the rest of the Joomla vulnerability database.
Rules current as of 11 October 2026.