Wekan: File Upload MIME Type Validation Bypass — Stored XSS via Missing System Binary Fallback (CVE-2026-68899) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-68899

Wekan: File Upload MIME Type Validation Bypass — Stored XSS via Missing System Binary Fallback

Answer in brief

CVE-2026-68899 records a Unknown severity vulnerability in Wekan: File Upload MIME Type Validation Bypass — Stored XSS via Missing System Binary Fallback. The current sources do not mark it as known exploited. The current feed maps wekan/wekan (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 19, 2026Updated Aug 19, 2026Source checked Aug 19, 2026First seen by HOL Aug 19, 2026Material review Aug 19, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps wekan/wekan (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
wekan/wekangeneric	< 9.90	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for wekan/wekan.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 19, 2026

Sources and claim methodology

Upstream source description

Wekan is open source kanban built with Meteor. Prior to 9.90, isFileValid() in models/fileValidation.js used the Unix file command for content-based MIME detection, but detectMimeFromFile() silently returned undefined when that binary was unavailable and the validation fell back to the attacker-controlled fileObj.type supplied through server/routes/attachmentApi.js. On deployments with WITH_API=true and no file binary, an authenticated board member could label HTML containing JavaScript as image/png, bypass the dangerous MIME check, and store active content under the Wekan origin for execution when another user opened it. Version 9.90 adds looksLikeDangerousMarkup() to inspect file bytes and force dangerous-content scanning when MIME detection is unavailable. This issue is fixed in version 9.90.

Quoted source text, attributed separately from HOL analysis.