Ninja Forms plugin for WordPress before 3.15.4 contains an incomplete server-side validation vulnerability that allows unauthenticated attackers to submit arbitrary values to Checkbox List, Multi-Select List, Image List, Country, and State fields because NF_Abstracts_List falls through to a validate() method that only checks required-field presence. Attackers can submit crafted formula payloads through the unauthenticated nf_ajax_submit endpoint that bypass CSV escaping applied only to Textbox and Textarea fields, resulting in CSV injection when an administrator downloads and opens the exported submissions file.
Published: 2026-10-28
Updated: 2026-10-29
Base Score: 7.5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P
Severity: High
Base Score: 7.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
Severity: High
Base Score: 5.1
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:L
Severity: Medium
EPSS: 0.00172