Ninja Forms CSV export deserializes public submission values
An unauthenticated visitor supplies serialized input through a public form. The value is later deserialized when an administrator exports submissions to CSV. Harmful file operations or code execution require a suitable object gadget chain in another installed component; the export does not identify one or disclose the input field or deserialization function. Administrator export is an explicit prerequisite. Authoritative affected range: 3.15.3 to < 3.15.4. Confirmed remediation: 3.15.4.
- Component
- Ninja Forms
- Plugin slug
ninja-forms- Affected
- 3.15.3 to < 3.15.4
- Safe version
3.15.4- Published
- Sep 22, 2026
This CVE was published Sep 22, 2026 and is one of 74 known issues for this plugin.
Update, patch or deactivate.
Update to the applicable fixed release identified in the authoritative export: 3.15.4. Avoid exporting untrusted submissions until updated. Treat submitted values as scalar data and never instantiate attacker-selected PHP objects during CSV generation; review or remove malicious historical submissions.
A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.
Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.
Technical description
The Ninja Forms WordPress plugin 3.15.3 does not prevent user-submitted form field values from being deserialised when an administrator later exports form submissions to CSV, allowing unauthenticated attackers to perform PHP Object Injection; if a suitable POP chain is present via another installed plugin or theme, this can lead to actions such as arbitrary file operations or remote code execution.
CVE / CNA vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H