Vulnerability · Published Jan 21, 2026 · Assigned by VulnCheck

CVE-2021-47870GetSimple CMS My SMTP Contact Plugin 1.1.2 - Stored XSS

Medium 4.8

In plain English

A medium-severity cross-site scripting in My SMTP Contact Plugin from GetSimple CMS. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities).

Severity (CVSS 4.0)4.8Medium

Exploit odds (30 days)0.3%top 79.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
GetSimple CMS	My SMTP Contact Plugin	1.1.2

Weakness: CWE-79 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

References

Full Disclosure Repository technical-description, exploit
Vendor Homepage product
GetSimple CMS GitHub Repository product
ExploitDB-49798 exploit
VulnCheck Advisory: GetSimple CMS My SMTP Contact Plugin 1.1.2 - Stored XSS third-party-advisory