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.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
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
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.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-103427 being exploited?
There is no known exploitation of CVE-2026-103427 in the wild and no public exploit code.
Sources
Also known as GHSA-39ch-8xp7-gcgh.