Answer in brief
CVE-2026-91127 records a High severity (CVSS 8.2) vulnerability in File Viewer: DOM XSS via unsafe hyperlink schemes in the legacy DOC renderer. The current sources do not mark it as known exploited. The current feed maps @file-viewer/doc (generic), flyfish-dev/file-viewer (generic), flyfish-dev/msdoc-viewer (generic), @file-viewer/doc (npm) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.2. 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.
The current feed maps @file-viewer/doc (generic), flyfish-dev/file-viewer (generic), flyfish-dev/msdoc-viewer (generic), @file-viewer/doc (npm) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| @file-viewer/docgeneric | < 2.3.1 | Not reported |
| flyfish-dev/file-viewergeneric | < 2.3.1 | Not reported |
| flyfish-dev/msdoc-viewergeneric | < 0.2.2 | Not reported |
| @file-viewer/docnpm | <=2.3.0 | 2.3.1 |
| @file-viewer/docnpm | >=0 <2.3.1 | 2.3.1 |
| msdoc-viewernpm | <=0.2.1 | 0.2.2 |
| msdoc-viewernpm | >=0 <0.2.2 | 0.2.2 |
Published upstream
Sep 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 18, 2026
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.
Quoted source text, attributed separately from HOL analysis.