CVE-2021-47870 GetSimple CMS My SMTP Contact Plugin 1.1.2 - Stored XSS
Attackers can inject arbitrary client-side code into the administrator's browser via stored XSS in the My SMTP Contact plugin.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2021-47870?
CVE-2021-47870 is a medium-severity cross-site scripting vulnerability in GetSimple CMS My SMTP Contact Plugin, published on 21 Jan 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
GetSimple CMS My SMTP Contact Plugin 1.1.2 suffers from a Stored Cross-Site Scripting (XSS) vulnerability. The plugin attempts to sanitize user input using htmlspecialchars(), but this can be bypassed by passing dangerous characters as escaped hex bytes. This allows attackers to inject arbitrary client-side code that executes in the administrator's browser when visiting a malicious page.
Weakness: CWE-79
Which versions are affected by CVE-2021-47870?
It affects 1 product.
Products include Get-Simple Getsimplecms.
How do I fix CVE-2021-47870?
No fix has been published for CVE-2021-47870 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-2021-47870 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47870 exists.
Other vulnerabilities in GetSimple CMS My SMTP Contact Plugin
Sources
Also known as GHSA-xcf5-jfw6-6364.