File Viewer: DOM XSS via unsafe hyperlink schemes in the legacy DOC renderer — GHSA-3753-M2X2-Q623

Summary

### Summary Before 2.3.1, the legacy `.doc` renderer emitted document hyperlink targets after HTML escaping but without a URL-scheme allowlist. A crafted `.doc` could therefore render a live `javascript:`, `vbscript:`, `data:`, or similarly unsafe link. Script could execute in the embedding origin if a viewer clicked it. ### Impact Applications rendering untrusted legacy `.doc` files with `@file-viewer/doc` or the…

Timeline

Published by source

2026-09-18

Risk context

• Reported severity or threat level: high.
• Reported CVSS score: 8.2 out of 10.
• Review exposure for the affected product or family: npm: @file-viewer/doc | npm: msdoc-viewer.

Product

npm: @file-viewer/doc | npm: msdoc-viewer

What to do

General, cautious steps (verify details in the official source):

• Prioritize patching or mitigation immediately (treat as actively risky).
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

Evidence and provenance

Canonical advisory ID

GHSA-3753-M2X2-Q623

Source

GitHub

Vendor

GitHub

Published by source

2026-09-18

Last source activity

2026-09-18

Additional identifiers

CVE-2026-91127

Curated by

hlukh.ch

Related advisories and connections

These advisories are connected by shared CVE, product, vendor, source, or time signals.