CVE-2026-52891
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedWekan 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceWekan prior to version 9.07 contains a command injection vulnerability in the avatar upload feature. The application embeds user-supplied filenames into paths used with child_process.exec() for MIME-type detection. Because models/avatars.js and models/fileValidation.js construct shell commands using the raw avatar filename, attackers can inject shell metacharacters (backticks, $()) to execute arbitrary commands on the server.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify Wekan installation method and versionCheck the Wekan version by querying the API at /api/version, inspecting the Docker image tag, or reviewing package.json if installed from source. Compare the version number to 9.07.Affected if The installed version is lower than 9.07 (e.g., 9.06, 9.05, etc.)
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Verify if avatar upload feature is accessibleCheck if the avatar upload endpoint exists by attempting a GET request to /avatars/upload or reviewing the Wekan web UI for avatar upload functionality. Inspect Wekan settings JSON or environment variables for avatar-related configuration flags.Affected if Avatar upload feature is enabled and accessible to users (even low-privileged ones)
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Review server logs for suspicious activityExamine Wekan server logs (typically in /var/log/wekan or Docker container stdout) for entries containing shell metacharacters like backticks (`), dollar-parentheses $(), or pipe symbols in avatar filename fields. Also check for unexpected child process spawn events.Affected if Logs contain filenames with shell metacharacters or unexpected command executions coinciding with avatar uploads
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Check for unexpected processes or files on the serverInspect running processes for unfamiliar commands, especially ones spawned from Node.js/Wekan parent processes. Look for new executable files in /tmp, /var/tmp, or Wekan's upload directories that were not explicitly uploaded by legitimate users.Affected if Unexpected processes are running or suspicious files appear in upload directories with timestamps matching potential exploitation periods
You are affected if Wekan version is below 9.07 AND the avatar upload feature is enabled and accessible to users in your environment.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade Wekan to version 9.07 or later. If immediate patching is not possible, disable avatar upload functionality until the upgrade can be applied.
Wekan 9.07
- Backup your Wekan installation and database before upgrading
- Upgrade Wekan to version 9.07 or later
- After upgrade, verify the avatar upload functionality works correctly
- Ensure the server is running the updated version by checking the Wekan UI or logs
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation3.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-52891 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-52891 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data