# CVE-2016-1209: Deserialization in n/a

> Remote attackers can execute arbitrary code via PHP object injection in the Ninja Forms WordPress plugin.

- **Severity:** Critical 9.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 May 2016
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-3qv8-hqcp-vhrh

## What is CVE-2016-1209?

CVE-2016-1209 is a critical unsafe deserialization vulnerability in Ninjaforms Ninja Forms, published on 14 May 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Ninja Forms plugin before 2.9.42.1 for WordPress allows remote attackers to conduct PHP object injection attacks via crafted serialized values in a POST request.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2016-1209?

It affects 1 product.


Products: Ninjaforms Ninja Forms.

## How do I fix CVE-2016-1209?

No fix has been published for CVE-2016-1209 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-1209 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2016-1209 exists.

Public exploit code:

- WordPress Plugin Ninja Forms 2.9.36 < 2.9.42 - File Upload (Metasploit) (exploitdb)
- WordPress Ninja Forms Unauthenticated File Upload (metasploit)

## Other vulnerabilities in Ninjaforms Ninja Forms

- [CVE-2025-9083](https://insights.sbomify.com/CVE-2025-9083/): Ninja-forms < 3.11.1 - Unauthenticated PHP Objection (critical 9.8)
- [CVE-2018-20981](https://insights.sbomify.com/CVE-2018-20981/): Information disclosure in n/a (critical 9.1)
- [CVE-2024-25572](https://insights.sbomify.com/CVE-2024-25572/): Cross-site request forgery in Ninja Forms (high 8.8)
- [CVE-2021-24163](https://insights.sbomify.com/CVE-2021-24163/): Ninja Forms < 3.4.34 - Authenticated SendWP Plugin Installation and Client Secret Key Disclosure (high 8.8)
- [CVE-2018-16308](https://insights.sbomify.com/CVE-2018-16308/): Other in n/a (high 8.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-1209 and fix it if it is affected.

What it is: CVE-2016-1209 is a critical unsafe deserialization vulnerability in Ninjaforms Ninja Forms, published on 14 May 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2016-1209 exists.

Affected product: Ninjaforms Ninja Forms. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2016-1209/ (Markdown: https://insights.sbomify.com/CVE-2016-1209/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-1209
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-1209
- OSV: https://osv.dev/vulnerability/CVE-2016-1209

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-1209/
Summaries are generated and may contain mistakes; the official description above is the record.