Cyber Resilience

CVE-2016-10045

RCE in Phpmailer Project Phpmailer ≤ 5.2.20

Public PoCHigh EPSSRCECommand Injection
Published
30 December 2016
Modified
06 May 2026
Patch / advisory
View advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.98 99.9th percentile
Risk Priority 97 floored blend · peak EPSS

Summary

CVE-2016-10045 is a critical-severity Command Injection (CWE-77) vulnerability in Phpmailer Project Phpmailer. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 0.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

The isMail transport in PHPMailer before 5.2.20 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code by leveraging improper interaction between the escapeshellarg function and internal escaping performed in the mail function…

more

in PHP. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-10033.

CWE(s)
CWE-77

Related Threats

Likely ATT&CK TechniquesAI

Techniques this vulnerability likely enables, inferred from its description, weakness type, and attributed-actor tradecraft. Confidence is per-technique.

T1190 Exploit Public-Facing Application Initial Accessconfidence: HIGH
Remote attackers can exploit the PHPMailer isMail transport to inject extra parameters into the mail command, enabling arbitrary code execution via command injection.
attack.mitre.org →
T1059.004 Unix Shell Executionconfidence: HIGH
The vulnerability allows injection of arguments into the system mail command, directly facilitating Unix shell command execution.
attack.mitre.org →
inferred from description + CWE · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2016-10033Same product: Joomla Joomla\!
CVE-2026-35223Same product: Joomla Joomla\!
CVE-2023-23751Same product: Joomla Joomla\!
CVE-2026-48958Same product: Joomla Joomla\!
CVE-2017-8917Same product: Joomla Joomla\!
CVE-2024-21726Same product: Joomla Joomla\!
CVE-2026-35221Same product: Joomla Joomla\!
CVE-2023-23752Same product: Joomla Joomla\!
CVE-2024-21724Same product: Joomla Joomla\!
CVE-2026-21629Same product: Joomla Joomla\!

Affected Assets

phpmailer project
phpmailer
≤ 5.2.20
wordpress
wordpress
≤ 4.7
joomla
joomla\!
1.5.0 — 3.6.5

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.2.3
  • V1.2.5
  • V1.2.8
  • V1.2.9

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input validation and neutralization that prevent command injection.

DE.CM-09 partial match
prevents

Runtime monitoring of software and data can detect anomalous command execution resulting from injection.

ID.RA-01 partial match
prevents

Identifying recorded vulnerabilities enables remediation of command-injection flaws before exploitation.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.28 Secure coding mostly match
prevents

Secure coding standards require proper escaping and parameterization of commands, directly eliminating CWE-77.

A.8.29 Security testing in development and acceptance mostly match
detects

Security testing in development catches command-injection vulnerabilities before release.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates input validation and command construction practices that directly prevent command injection.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly call for controls against injection flaws including command injection.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles reduce the attack surface but do not prescribe the specific neutralization techniques needed.

A.8.31 Separation of development, test and production environments none match
none

Environment separation limits the blast radius of an exploited command injection but does not prevent the flaw itself.

References