CVE-2026-104847: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in ProseMirror prosemirror-view
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.
AI Analysis
Technical Summary
ProseMirror's prosemirror-view component improperly neutralizes input during web page generation, specifically in its paste handling functionality. Before version 1.42.3, it accepts HTML content from the clipboard whose context attributes are not validated against the schema, allowing an attacker to craft HTML that executes arbitrary JavaScript in the browser when pasted into the editor. This is a classic cross-site scripting (CWE-79) vulnerability. The vulnerability has a CVSS 4.0 base score of 8.5, indicating high severity. The fix is included in version 1.42.3.
Potential Impact
An attacker can execute arbitrary JavaScript in the context of the user's browser by tricking a user into pasting malicious HTML content into the ProseMirror editor. This can lead to theft of sensitive information, session hijacking, or other malicious actions within the affected browser session. The vulnerability requires user interaction (pasting) and no privileges or authentication are needed to exploit it.
Mitigation Recommendations
Upgrade prosemirror-view to version 1.42.3 or later, where this vulnerability is fixed. No other mitigations are specified. Patch status is confirmed fixed in 1.42.3.
CVE-2026-104847: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in ProseMirror prosemirror-view
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.
CVSS v4.0
Score 8.5high
Affected software
ProseMirror
prosemirror-view
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
ProseMirror's prosemirror-view component improperly neutralizes input during web page generation, specifically in its paste handling functionality. Before version 1.42.3, it accepts HTML content from the clipboard whose context attributes are not validated against the schema, allowing an attacker to craft HTML that executes arbitrary JavaScript in the browser when pasted into the editor. This is a classic cross-site scripting (CWE-79) vulnerability. The vulnerability has a CVSS 4.0 base score of 8.5, indicating high severity. The fix is included in version 1.42.3.
Potential Impact
An attacker can execute arbitrary JavaScript in the context of the user's browser by tricking a user into pasting malicious HTML content into the ProseMirror editor. This can lead to theft of sensitive information, session hijacking, or other malicious actions within the affected browser session. The vulnerability requires user interaction (pasting) and no privileges or authentication are needed to exploit it.
Mitigation Recommendations
Upgrade prosemirror-view to version 1.42.3 or later, where this vulnerability is fixed. No other mitigations are specified. Patch status is confirmed fixed in 1.42.3.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-10-02T14:38:43.243Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6abfd8f5a43b0b3b89d5a0ef
Added to database: 10/02/2026, 16:16:53 UTC
Last enriched: 10/02/2026, 16:31:03 UTC
Last updated: 10/03/2026, 03:11:15 UTC
Views: 12
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