What is CVE-2026-52891?
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.
The record classifies CVE-2026-52891 under weakness classes CWE-78, CWE-88. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 82 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 9.9 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - EPSS (FIRST)
- 0.4% probability of exploitation in the next 30 days, higher than 32.5% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 6.3/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-07-15
Is CVE-2026-52891 being exploited?
It currently carries a trending score of 38 in the Threadlinqs vulnerability feed.
Affected products and versions
- wekan: wekan
How to fix CVE-2026-52891
No vendor patch reference has been recorded for CVE-2026-52891 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-52891
No threat campaign in the Threadlinqs corpus currently references CVE-2026-52891, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.