CVE-2026-52891: Wekan: Shell Injection via Avatar Upload

Severity: critical (CVSS 9.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-15 · updated 2026-07-17
Weakness: CWE-78

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.

Affected products

WeKan: before 9.07

References

https://github.com/wekan/wekan/commit/a4c74a5980e9f778eb444fd346f32aa3d16786a9
https://github.com/wekan/wekan/releases/tag/v9.07
https://github.com/wekan/wekan/security/advisories/GHSA-35j7-h385-2q9g

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