# CVE-2026-5399: Redux Framework <= 4.5.13.1 - Authenticated (Subscriber+) Stored Cross-Site Scripting via Slider Field Value

> Authenticated attackers can inject scripts into user profiles via slider fields, executing code when administrators view the profile.

- **Severity:** Medium 6.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 Sep 2026
- **Updated:** 10 Sep 2026
- **Also known as:** GHSA-hvw8-fmqf-2f96

## What is CVE-2026-5399?

CVE-2026-5399 is a medium-severity cross-site scripting vulnerability in davidanderson Redux Framework, published on 10 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The Redux Framework plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Slider field in User Profile settings in versions up to and including 4.5.13.1. This is due to insufficient input sanitization in the user_meta_save() function (which only sanitizes array values, not scalar values) and improper output escaping in the Redux_Slider::render() method, which outputs slider values into unquoted HTML attributes. The vulnerability also exploits the fact that the clean_default() method only casts values to numeric types when they are empty or out of bounds, allowing malicious strings like '1 tabindex=0 autofocus onfocus=alert(1) x=' to pass validation through PHP's loose type comparison. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject arbitrary web scripts into their user profile that will execute whenever an Administrator navigates to view the attacker's profile page.

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

## Which versions are affected by CVE-2026-5399?


## How do I fix CVE-2026-5399?

No fix has been published for CVE-2026-5399 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-5399 being exploited?

There is no known exploitation of CVE-2026-5399 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5399 and fix it if it is affected.

What it is: CVE-2026-5399 is a medium-severity cross-site scripting vulnerability in davidanderson Redux Framework, published on 10 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-5399 in the wild and no public exploit code.

Affected product: davidanderson Redux Framework. 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-2026-5399/ (Markdown: https://insights.sbomify.com/CVE-2026-5399/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5399
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5399
- OSV: https://osv.dev/vulnerability/CVE-2026-5399

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-5399/
Summaries are generated and may contain mistakes; the official description above is the record.