vulntracker.iovulntracker.io
© 2026 vulntracker.io

CVE-2026-91127

File Viewer: DOM XSS via unsafe hyperlink schemes in the legacy DOC renderer

HIGH
8.2
CVSS Score
Published: September 18, 2026 at 05:18 PM UTC
Updated: September 24, 2026 at 09:37 PM UTC
3 products affected across 2 vendorsMsdoc ViewerDocFile Viewer

Using file-viewer by flyfish-dev?

Get instant alerts when new vulnerabilities affect file-viewer - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Start FreeSign In
Severity
HIGH8.2
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Doc· Fileviewer
60%
v < 2.3.1
Affected range stops below 2.3.1, so it looks safe — our inference, not a vendor statement
File Viewer· Flyfish Dev
60%
v < 2.3.1
Affected range stops below 2.3.1, so it looks safe — our inference, not a vendor statement
Msdoc Viewer· Flyfish Dev
60%
v < 0.2.2
Affected range stops below 0.2.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (3)

x_refsource_CONFIRM
Source: cverecord
https://github.com/flyfish-dev/file-viewer/security/advisories/GHSA-3753-m2x2-q623
x_refsource_MISC
Source: cverecord
https://github.com/flyfish-dev/file-viewer/commit/ef045680f8d9830a3eee9612f7df46a734361b07
x_refsource_MISC
Source: cverecord
https://github.com/flyfish-dev/file-viewer/releases/tag/v2.3.1

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.2HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
HIGH
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-79CWE-83

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Create accountSign in
Free plan, no card