CVE-2026-15256: unknown ninja forms Injection

Vulnerability summary

CVE-2026-15256 is a medium (CVSS 5.3) Injection vulnerability in unknown ninja forms. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 14.4% of scored vulnerabilities. 1 public exploit is recorded. Fixed in 3.14.10.

Timeline

1. 06-08-2026
   PublishedVulnerability first disclosed.
2. 07-08-2026
   Last modifiedVulnerability information updated.

Description

The Ninja Forms WordPress plugin before 3.14.10 does not prevent user-supplied query-string input, used to pre-populate a form field's default value, from being processed as a shortcode, allowing unauthenticated attackers to execute arbitrary shortcodes registered on the site when a form so configured is embedded on a public page.

• CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
• CWE-94Improper Control of Generation of Code ('Code Injection')The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.