ProseMirror: XSS vulnerability in prosemirror-view's paste handling
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Active
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-79.
Summary
ProseMirror's view component renders and manages the editable browser interface for ProseMirror documents. Prior to 1.42.3, prosemirror-view paste handling accepts attacker-provided HTML whose clipboard slice context contains attributes that are not passed through schema attribute validation. When a user pastes the crafted HTML into an editor, the unvalidated context attributes can construct content that executes attacker-controlled JavaScript in the browser window containing the editor. This issue is fixed in version 1.42.3.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| ProseMirror | prosemirror-view | before 1.42.3 | 1.42.3 | Patch available | CNA |
| — | prosemirror-view (npm) | before 1.42.3 | 1.42.3 | Patch available | GHSA-c8x8-7fp4-3x9w |
- prosemirror-view VendorProseMirror Affected before 1.42.3 Fixed in 1.42.3 Patch available CNA
- prosemirror-view (npm) Vendor— Affected before 1.42.3 Fixed in 1.42.3 Patch available GHSA-c8x8-7fp4-3x9w
Remediation
- Fix · CNA prosemirror-view (ProseMirror) Fixed in 1.42.3
- Fix · GHSA-c8x8-7fp4-3x9w prosemirror-view (npm) Fixed in 1.42.3 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-104847
- 2026-10-06 Alias added: GHSA-c8x8-7fp4-3x9w
- 2026-10-06 Fix available: npm/[email protected] · GHSA-c8x8-7fp4-3x9w
- 2026-10-06 CVSS score added · GHSA-c8x8-7fp4-3x9w
- 2026-10-06 Weakness changed · GHSA-c8x8-7fp4-3x9w
- 2026-10-06 5 new references · GHSA-c8x8-7fp4-3x9w
References
Other 4
- https://github.com/ProseMirror/prosemirror-view/security/advisories/GHSA-c8x8-7fp4-3x9w
- https://github.com/ProseMirror/prosemirror-view/commit/20dc0a911a79f8fc6640dbbea5e7d68d3c4784b7
- https://github.com/ProseMirror/prosemirror-view/commit/2e91a612bbc1248e55b4f6061fc93fe459f977c1
- https://github.com/ProseMirror/prosemirror-view
Sources
- CVE-2026-104847 · CVE Program
- CVE-2026-104847 · NVD
- FIRST EPSS
- GHSA-c8x8-7fp4-3x9w · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences