CVE-2026-86813: medium-severity vulnerability in MetForm
MetForm < 4.1.9 - Unauthenticated Email Header Injection via Notification Reply-To
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
33Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 4.8epss 0.2%
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.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Affected products
Unknown · MetFormpublic PoCs found — 1
cve_referencewpscan.com/vulnerability/afda2a26-b965-42cb-85a8-4a4d83ec026e/unverified⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
Related CVEs — MetForm
In the same product, most dangerous first.
CVE-2026-86832MEDIUMMetForm < 4.3.1 - Unauthenticated Form Entry Data Disclosure via REST APIEPSS 0.2%CVE-2026-86834LOWMetForm 2.2.1 - 4.3.0 - Unauthenticated Debug File Disclosure via HubSpot Forms IntegrationEPSS 0.2%CVE-2026-86833MEDIUMMetForm < 4.3.1 - Unauthenticated HTML Injection in Notification Emails via Field ShortcodesEPSS 0.2%