Description
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.
References6
- github.com/ProseMirror/prosemirror-view/commit/20dc0a911a79f8fc…
- github.com/ProseMirror/prosemirror-view/commit/2e91a612bbc1248e…
- github.com/ProseMirror/prosemirror-view/security/advisories/GHS…
- github.com/ProseMirror/prosemirror-view/security/advisories/GHS…
- github.com/ProseMirror/prosemirror-view/security/advisories/GHS…
- github.com/ProseMirror/prosemirror-view/security/advisories/GHS…
Metrics
- CVSS 4.0
-
8.5
HIGH
Score source: CNA
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 23 · as of 10 November 2026
- CWE
- CWE-79
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.