High 8.2Published Sep 18, 2026

CVE-2026-91127File Viewer: DOM XSS via unsafe hyperlink schemes in the legacy DOC renderer

Updated under an hour ago (2026-10-19 09:50 UTC)

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It affects flyfish-dev file-viewer and 2 other products. Add what you run to find out whether that includes you.

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Every CVE for flyfish-dev file-viewer

Exploited in the last 30 days

File Viewer is a browser-native viewer for Office, PDF, CAD, archive, and other files in private and internal web applications. Prior to @file-viewer/doc 2.3.1 and msdoc-viewer 0.2.2, the legacy DOC renderer emitted document-controlled hyperlink targets into generated HTML after character escaping but without restricting URL schemes. A crafted legacy DOC file could place javascript:, vbscript:, data:, or another unsafe scheme in a rendered link, and script could execute in the embedding application's origin when a user clicked the link. The fix blocks external document links by default, allows only HTTP(S), mail, telephone, safe relative URLs, and internal bookmarks when external links are explicitly enabled, and applies mount-boundary sanitization as defense in depth. This issue is fixed in @file-viewer/doc 2.3.1 and msdoc-viewer 0.2.2.

CVSS: 8.2 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N
Weakness (CWE): CWE-79, CWE-83
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Sep 22, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

flyfish-dev file-viewer flyfish_dev:file_viewer (from the name)	before 2.3.1	CNA record
@file-viewer doc file_viewer:doc (from the name)	before 2.3.1	CNA record
flyfish-dev msdoc-viewer flyfish_dev:msdoc_viewer (from the name)	before 0.2.2	CNA record

References

https://github.com/flyfish-dev/file-viewer/security/advisories/GHSA-3753-m2x2-q623x-refsource-confirm
https://github.com/flyfish-dev/file-viewer/commit/ef045680f8d9830a3eee9612f7df46a734361b07x-refsource-misc
https://github.com/flyfish-dev/file-viewer/releases/tag/v2.3.1x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.