CVE-2016-10033VulnerabilityPublished 07/07/2025Updated 10/24/2026
CVE-2016-10033: PHPMailer Command Injection Vulnerability
Affects PHP PHPMailerSource CISA KEV
Severity
HighNo CVSS score published yet
- Exploitation
Actively exploited – in CISA KEV since 07/07/2025
- KEV deadline
- 07/28/2025
- EPSS
- 99.7% chance of exploitation in 30 days – higher than 99% of CVEs
What to do
CISA required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Description
PHPMailer contains a command injection vulnerability because it fails to sanitize user-supplied input. Specifically, this issue affects the 'mail()' function of 'class.phpmailer.php' script. An attacker can exploit this issue to execute arbitrary code within the context of the application. Failed exploit attempts will result in a denial-of-service condition.