# CVE-2026-96558: Cross-site scripting in Quiz and Survey Master (QSM) – Quiz Maker & Survey Maker

> Unauthenticated attackers can inject arbitrary scripts via the qsm_hidden_questions parameter, leading to stored XSS when users view affected pages.

- **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:** 10 Oct 2026
- **Updated:** 11 Oct 2026
- **Also known as:** GHSA-ff7g-f75x-5gp5

## What is CVE-2026-96558?

CVE-2026-96558 is a high-severity cross-site scripting vulnerability in expresstech Quiz and Survey Master (QSM) – Quiz Maker & Survey Maker, published on 10 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Quiz and Survey Master (QSM) – Quiz Maker & Survey Maker plugin for WordPress is vulnerable to Stored DOM-Based Cross-Site Scripting via the 'qsm_hidden_questions' parameter in all versions up to, and including, 11.2.6 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. This requires the attacker to force the mlw_results INSERT to fail by submitting an over-length or duplicate qsm_unique_key value, which triggers the audit trail code branch that writes the unescaped payload to wp_mlw_qm_audit_trail.form_data.

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

## Which versions are affected by CVE-2026-96558?


## How do I fix CVE-2026-96558?

No fix has been published for CVE-2026-96558 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-96558 being exploited?

There is no known exploitation of CVE-2026-96558 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-96558 and fix it if it is affected.

What it is: CVE-2026-96558 is a high-severity cross-site scripting vulnerability in expresstech Quiz and Survey Master (QSM) – Quiz Maker & Survey Maker, published on 10 Oct 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-2026-96558 in the wild and no public exploit code.

Affected product: expresstech Quiz and Survey Master (QSM) – Quiz Maker & Survey Maker. 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-2026-96558/ (Markdown: https://insights.sbomify.com/CVE-2026-96558/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-96558
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-96558
- OSV: https://osv.dev/vulnerability/CVE-2026-96558

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-96558/
Summaries are generated and may contain mistakes; the official description above is the record.