CVE-2026-52891 Wekan: Shell Injection via Avatar Upload
Attackers can execute arbitrary commands on the server by uploading avatars with malicious filenames containing shell metacharacters.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-52891?
CVE-2026-52891 is a critical command injection vulnerability in wekan, published on 15 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Wekan is open source kanban built with Meteor. Prior to 9.07, Wekan avatar upload functionality embeds user-supplied filenames into paths later passed to child_process.exec() for MIME-type detection. Because models/avatars.js and models/fileValidation.js used a shell command with the avatar filename, shell metacharacters such as backticks and $() in the filename could execute commands on the server. This issue is fixed in version 9.07.
Which versions are affected by CVE-2026-52891?
How do I fix CVE-2026-52891?
No fix has been published for CVE-2026-52891 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-52891 being exploited?
There is no known exploitation of CVE-2026-52891 in the wild and no public exploit code.
Sources
Also known as GHSA-35j7-h385-2q9g.