# CVE-2026-15664: Cross-site scripting in Quill Forms | Conversational Multi Step Forms, Surveys & quizzes

> Unauthenticated attackers can inject scripts via form fields that execute in the admin view, potentially compromising administrator accounts.

- **Severity:** High 7.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Sep 2026
- **Updated:** 19 Sep 2026
- **Also known as:** GHSA-6hvq-jpx9-cm24

## What is CVE-2026-15664?

CVE-2026-15664 is a high-severity cross-site scripting vulnerability in mdmag Quill Forms | Conversational Multi Step Forms, Surveys & quizzes, published on 19 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Quill Forms | Conversational Multi Step Forms, Surveys & quizzes plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Multiple Choice 'Other' Value in all versions up to, and including, 5.7.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The injected script executes in the context of the WordPress admin results view, making administrators the primary target when reviewing submitted form entries.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-15664?


## How do I fix CVE-2026-15664?

No fix has been published for CVE-2026-15664 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-15664 being exploited?

There is no known exploitation of CVE-2026-15664 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-15664 and fix it if it is affected.

What it is: CVE-2026-15664 is a high-severity cross-site scripting vulnerability in mdmag Quill Forms | Conversational Multi Step Forms, Surveys & quizzes, published on 19 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-15664 in the wild and no public exploit code.

Affected product: mdmag Quill Forms | Conversational Multi Step Forms, Surveys & quizzes. 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-2026-15664/ (Markdown: https://insights.sbomify.com/CVE-2026-15664/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-15664
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-15664
- OSV: https://osv.dev/vulnerability/CVE-2026-15664

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-15664/
Summaries are generated and may contain mistakes; the official description above is the record.