Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
The prosemirror-view npm package, versions before 1.42.3, has a cross-site scripting flaw in its paste handling. An attacker can supply HTML that, when pasted into a ProseMirror editor, runs attacker-controlled JavaScript in the browser window containing the editor. Upgrade prosemirror-view to version 1.42.3, which adds validation that prevents this; the source lists no workarounds.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 8.5 | High | 4.0 | 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 | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0030, the 23rd percentile, on 13 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 13:34 UTC First seen by agentprime
- 31 Oct 2026, 13:34 UTC Confirmed by OSV
Sources
- GitHub Advisory Database: GHSA-c8x8-7fp4-3x9w
- OSV: GHSA-c8x8-7fp4-3x9w
- github.com/ProseMirror/prosemirror-view/security/advisories/GHSA-c8x8-7fp4-3x9w
- nvd.nist.gov/vuln/detail/CVE-2026-104847
- github.com/ProseMirror/prosemirror-view/commit/20dc0a911a79f8fc6640dbbea5e7d68d3c4784b7
- github.com/ProseMirror/prosemirror-view/commit/2e91a612bbc1248e55b4f6061fc93fe459f977c1
- github.com/ProseMirror/prosemirror-view