Answer in brief
CVE-2026-100155 records a Medium severity (CVSS 6.5) vulnerability in Ninja Forms <= 3.15.5 - Unauthenticated Arbitrary Shortcode Execution via 'formData' Field Value via Success Message Merge Tag. The current sources do not mark it as known exploited. The current feed maps kstover/Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder (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 6.5. 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 kstover/Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| kstover/Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Buildergeneric | >=0 <=3.15.5 | Not reported |
Published upstream
Oct 31, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 31, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 31, 2026
The The Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder plugin for WordPress is vulnerable to arbitrary shortcode execution in all versions up to, and including, 3.15.5 This is due to the software allowing users to execute an action that does not properly validate a value before running do_shortcode. This makes it possible for unauthenticated attackers to execute arbitrary shortcodes.
Quoted source text, attributed separately from HOL analysis.