CVE-2026-104847: Prosemirror view Cross-Site Scripting Vulnerability

HIGH
Advisory Identifier: GHSA-c8x8-7fp4-3x9w
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CWE-79
Published
Advisory Summary

CVE-2026-104847 is a HIGH cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Prosemirror view libraries in the npm ecosystem. The issue involves prosemirror has a xss vulnerability in prosemirror-view's paste handling. Remediation is available by upgrading affected packages to version 1.42.3.

CVE-2026-104847 at a Glance

CVE Identifier CVE-2026-104847
GHSA Identifier GHSA-c8x8-7fp4-3x9w
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Prosemirror view
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-104847

To remediate this vulnerability, upgrade all affected Prosemirror view dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

prosemirror-view fixed: 1.42.3 
npm install prosemirror-view@1.42.3
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls prosemirror-view

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-104847, inspect your project dependencies using npm:

npm ls prosemirror-view

Analyze the terminal output to locate any version of Prosemirror view in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.42.3), your application is affected.

Note: The npm ls prosemirror-view command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Prosemirror view, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact When a user pastes attacker-provided HTML into a ProseMirror editor component, this can cause attacker-controlled JavaScript code to run in the browser window containing the editor. ### Patches Version 1.42.3 adds validation that prevents this attack. ### Workarounds No known workarounds.

CVE-2026-104847 Affected Prosemirror view Versions

1 component(s)
Fixed Versions:
1.42.3
Product / Package Ecosystem Affected Versions Fixed Version
prosemirror-view
npm/prosemirror-view
npm
< 1.42.3
1.42.3

References

GitHub Advisory / Wiki ADVISORY
https://github.com/ProseMirror/prosemirror-view/security/advisories/GHSA-c8x8-7fp4-3x9w
NVD — CVE-2026-104847 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-104847
Security Fix Commit FIX COMMIT
https://github.com/ProseMirror/prosemirror-view/commit/20dc0a911a79f8fc6640dbbea5e7d68d3c4784b7
Security Fix Commit FIX COMMIT
https://github.com/ProseMirror/prosemirror-view/commit/2e91a612bbc1248e55b4f6061fc93fe459f977c1
Prosemirror view Source Repository REPOSITORY
https://github.com/ProseMirror/prosemirror-view

Frequently Asked Questions

What is CVE-2026-104847?
CVE-2026-104847 is a security vulnerability in Prosemirror view involving ProseMirror has a XSS vulnerability in prosemirror-view's paste handling under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Prosemirror view versions are affected?
Affected versions include releases prior to 1.42.3 across affected packages: prosemirror-view.
What version fixes CVE-2026-104847?
Upgrading to 1.42.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is prosemirror-view affected?
Yes, prosemirror-view is affected in releases prior to 1.42.3. Upgrade your dependency to 1.42.3 or later.
What CWE is associated with CVE-2026-104847?
CVE-2026-104847 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check npm dependencies for CVE-2026-104847?
Run the dependency tree command: 'npm ls prosemirror-view'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-c8x8-7fp4-3x9w",
  "modified" : "2026-10-05T22:36:06Z",
  "published" : "2026-10-05T22:36:06Z",
  "aliases" : [ "CVE-2026-104847" ],
  "summary" : "ProseMirror has a XSS vulnerability in prosemirror-view's paste handling",
  "details" : "### Impact\n\nWhen a user pastes attacker-provided HTML into a ProseMirror editor component, this can cause attacker-controlled JavaScript code to run in the browser window containing the editor.\n\n### Patches\n\nVersion 1.42.3 adds validation that prevents this attack.\n\n### Workarounds\n\nNo known workarounds.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "prosemirror-view"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.42.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/ProseMirror/prosemirror-view/security/advisories/GHSA-c8x8-7fp4-3x9w"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-104847"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ProseMirror/prosemirror-view/commit/20dc0a911a79f8fc6640dbbea5e7d68d3c4784b7"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ProseMirror/prosemirror-view/commit/2e91a612bbc1248e55b4f6061fc93fe459f977c1"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/ProseMirror/prosemirror-view"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-05T22:36:06Z",
    "nvd_published_at" : "2026-10-02T16:16:47Z"
  }
}