# CVE-2026-103427: Simple Membership <= 4.8.4 - Authenticated (Subscriber+) Stored Cross-Site Scripting via Country Field

> Authenticated attackers can inject arbitrary scripts via the country field, potentially leading to session hijacking or malicious actions on behalf of other users.

- **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 Oct 2026
- **Updated:** 11 Oct 2026
- **Also known as:** GHSA-39ch-8xp7-gcgh

## What is CVE-2026-103427?

CVE-2026-103427 is a medium-severity cross-site scripting vulnerability in wpinsider-1 Simple Membership, published on 10 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The Simple Membership plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'country' parameter in all versions up to, and including, 4.8.4 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Unauthenticated attackers may also exploit this vulnerability when the plugin's Enable Free Membership feature is turned on, as it permits anonymous front-end registration and profile submission.

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

## Which versions are affected by CVE-2026-103427?


## How do I fix CVE-2026-103427?

No fix has been published for CVE-2026-103427 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-103427 being exploited?

There is no known exploitation of CVE-2026-103427 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-103427 and fix it if it is affected.

What it is: CVE-2026-103427 is a medium-severity cross-site scripting vulnerability in wpinsider-1 Simple Membership, published on 10 Oct 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-2026-103427 in the wild and no public exploit code.

Affected product: wpinsider-1 Simple Membership. 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-2026-103427/ (Markdown: https://insights.sbomify.com/CVE-2026-103427/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-103427
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-103427
- OSV: https://osv.dev/vulnerability/CVE-2026-103427

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-103427/
Summaries are generated and may contain mistakes; the official description above is the record.