Vulnerability · Published Sep 11, 2026 · Assigned by WPScan
CVE-2026-86813MetForm < 4.1.9 - Unauthenticated Email Header Injection via Notification Reply-To
Medium 4.8
In plain English
A medium-severity security flaw in MetForm from Unknown. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities).
Severity (CVSS 3.1)4.8Medium
Exploit odds (30 days)0.2%top 84.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
The MetForm WordPress plugin before 4.1.9 does not properly neutralize newline characters in user-submitted values that are placed into notification email headers, allowing unauthenticated attackers to inject additional email headers, such as Bcc, into the emails the site sends when a submitted field value is configured to populate a header.
Affected products (as reported)
Weakness: CWE-93 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
References
- https://wpscan.com/vulnerability/afda2a26-b965-42cb-85a8-4a4d83ec026e/ exploit, vdb-entry, technical-description