CVE-2026-91827 Ninja Forms 3.15.3 - Unauthenticated PHP Object Injection via CSV Export

High 7.5 Published Updated

Unauthenticated attackers can trigger PHP object injection via CSV export, potentially leading to remote code execution or file operations if a suitable gadget chain exists.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
None listed

What is CVE-2026-91827?

CVE-2026-91827 is a high-severity unsafe deserialization vulnerability in Unknown Ninja Forms, published on 22 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official 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.

Weakness: CWE-502

Which versions are affected by CVE-2026-91827?

How do I fix CVE-2026-91827?

No fix has been published for CVE-2026-91827 yet. Limit exposure of the affected software until one is available.

Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.

Is CVE-2026-91827 being exploited?

There is no known exploitation of CVE-2026-91827 in the wild and no public exploit code.

Sources

Also known as GHSA-jvgp-rj42-qjww.

Is CVE-2026-91827 in your software?

Upload an SBOM and sbomify checks it against every vulnerability here, every day.

Check your SBOMs for free