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CVE-2026-91127 (GCVE-0-2026-91127)

Vulnerability from cvelistv5 – Published: 2026-09-18 17:18 – Updated: 2026-09-18 17:18
VLAI
Title
File Viewer: DOM XSS via unsafe hyperlink schemes in the legacy DOC renderer
Summary
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.
Severity
8.2 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  • CWE-83 - Improper Neutralization of Script in Attributes in a Web Page
Assigner
References
Impacted products
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "file-viewer",
          "vendor": "flyfish-dev",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.3.1"
            }
          ]
        },
        {
          "product": "doc",
          "vendor": "@file-viewer",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.3.1"
            }
          ]
        },
        {
          "product": "msdoc-viewer",
          "vendor": "flyfish-dev",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.2.2"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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\u0027s 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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 8.2,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-83",
              "description": "CWE-83: Improper Neutralization of Script in Attributes in a Web Page",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-18T17:18:40.370Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/flyfish-dev/file-viewer/security/advisories/GHSA-3753-m2x2-q623",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/flyfish-dev/file-viewer/security/advisories/GHSA-3753-m2x2-q623"
        },
        {
          "name": "https://github.com/flyfish-dev/file-viewer/commit/ef045680f8d9830a3eee9612f7df46a734361b07",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/flyfish-dev/file-viewer/commit/ef045680f8d9830a3eee9612f7df46a734361b07"
        },
        {
          "name": "https://github.com/flyfish-dev/file-viewer/releases/tag/v2.3.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/flyfish-dev/file-viewer/releases/tag/v2.3.1"
        }
      ],
      "source": {
        "advisory": "GHSA-3753-m2x2-q623",
        "discovery": "UNKNOWN"
      },
      "title": "File Viewer: DOM XSS via unsafe hyperlink schemes in the legacy DOC renderer"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-91127",
    "datePublished": "2026-09-18T17:18:40.370Z",
    "dateReserved": "2026-09-14T19:36:48.844Z",
    "dateUpdated": "2026-09-18T17:18:40.370Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "file-viewer",
                "vendor": "flyfish-dev",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003c 2.3.1"
                  }
                ]
              },
              {
                "product": "doc",
                "vendor": "@file-viewer",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003c 2.3.1"
                  }
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              },
              {
                "product": "msdoc-viewer",
                "vendor": "flyfish-dev",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003c 0.2.2"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "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\u0027s 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."
          }
        ],
        "id": "CVE-2026-91127",
        "lastModified": "2026-09-18T18:18:02.250",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 8.2,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "LOW",
                "privilegesRequired": "NONE",
                "scope": "CHANGED",
                "userInteraction": "REQUIRED",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 2.8,
              "impactScore": 4.7,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-09-18T18:18:02.250",
        "references": [
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/flyfish-dev/file-viewer/commit/ef045680f8d9830a3eee9612f7df46a734361b07"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/flyfish-dev/file-viewer/releases/tag/v2.3.1"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/flyfish-dev/file-viewer/security/advisories/GHSA-3753-m2x2-q623"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Received",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-79"
              },
              {
                "lang": "en",
                "value": "CWE-83"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Primary"
          }
        ]
      }
    }
  }
}



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