# CVE-2026-10818: WPForms Pro <= 1.10.1.1 - Unauthenticated Arbitrary File Write via Chunked Upload Init/Finalize Ordering

> Unauthenticated attackers can upload executable files via chunked upload flaws, leading to remote code execution on sites using WPForms Pro.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:H/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:** 25 Jul 2026
- **Updated:** 27 Jul 2026
- **Also known as:** GHSA-g685-9q2w-88f4

## What is CVE-2026-10818?

CVE-2026-10818 is a high-severity vulnerability in WPForms Pro, published on 25 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The WPForms Pro plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 1.10.1.1 via the ajax_chunk_upload_finalize function. This is due to the file type validation occurring after chunk metadata and file contents have already been written to disk, and the assembled file not being deleted upon validation failure. This makes it possible for unauthenticated attackers to upload files that may be executable, which makes remote code execution possible.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type)

## Which versions are affected by CVE-2026-10818?


## How do I fix CVE-2026-10818?

No fix has been published for CVE-2026-10818 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-10818 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-10818 exists.

Public exploit code:

- WPForms Pro <= 1.10.1.1 - Unauthenticated Arbitrary File Write via Chunked Upload Init/Finalize Ordering (github_poc): https://github.com/Nxploited/CVE-2026-10818
- WPForms Pro <= 1.10.1.1 - Unauthenticated Arbitrary File Upload (nuclei): http/cves/2026/CVE-2026-10818.yaml

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-10818 and fix it if it is affected.

What it is: CVE-2026-10818 is a high-severity vulnerability in WPForms Pro, published on 25 Jul 2026. 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-2026-10818 exists.

Affected product: WPForms Pro. 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-2026-10818/ (Markdown: https://insights.sbomify.com/CVE-2026-10818/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-10818
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-10818
- OSV: https://osv.dev/vulnerability/CVE-2026-10818

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-10818/
Summaries are generated and may contain mistakes; the official description above is the record.