Answer in brief
CVE-2026-86833 records a Medium severity (CVSS 5.4) vulnerability in MetForm < 4.3.1 - Unauthenticated HTML Injection in Notification Emails via Field Shortcodes. The current sources do not mark it as known exploited. The current feed maps Unknown/MetForm (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.4. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Unknown/MetForm (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Unknown/MetFormgeneric | >=0 <4.3.1 | 4.3.1 |
Published upstream
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 7, 2026
The MetForm WordPress plugin before 4.3.1 does not sanitize or escape submitted form-field values before inserting them into the HTML body of its email notifications, allowing unauthenticated attackers to inject arbitrary markup into the administrator and submitter notification emails the site sends.
Quoted source text, attributed separately from HOL analysis.