CVE-2015-8476: Multiple CRLF injection vulnerabilities in PHPMailer before 5.2.14 allow attackers to inject arbitrary SMTP co

Q: How do I fix CVE-2015-8476?

debian linux: mitigate or apply the listed mitigation; phpmailer: upgrade to newer than 5.2.13. Exact commands for each OS are on this page.

Q: Is CVE-2015-8476 being exploited?

CVE-2015-8476 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2015-8476 affect?

CVE-2015-8476 affects debian linux, phpmailer. Severity is medium (CVSS 5.0). Multiple CRLF injection vulnerabilities in PHPMailer before 5.2.14 allow attackers to inject arbitrary SMTP commands via CRLF sequences in an (1) email address to the validateAddress function in class.phpmailer.php or (2) SMTP command to th

Q: How urgent is CVE-2015-8476?

Priority 43/100. On your watchlist

This month

MEDIUM 5.0WATCHLISTMITIGATEUPGRADE

CVE-2015-8476 is a medium-severity flaw (CVSS 5.0) affecting debian linux, phpmailer. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Multiple CRLF injection vulnerabilities in PHPMailer before 5.2.14 allow attackers to inject arbitrary SMTP commands via CRLF sequences in an (1) email address to the validateAddress function in class.phpmailer.php or (2) SMTP command to the sendCommand function in class.smtp.php, a different vulnerability than CVE-2012-0796.

Why this priority

On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	2.0% (top 19%)
CISA exploited list	No
Weakness	CWE-20
Published	2015-12-16
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: debian · phpmailer project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2015-12-16 21:59 UTCPublished CVE record published
2026-06-17 00:34 UTCUpdated Record last modified

debian debian linux MITIGATE

Affected: 6.0 · 7.0 · 8.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

phpmailer project phpmailer UPGRADE

Affected: <= 5.2.13

Fixed in: newer than 5.2.13

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy phpmailer || rpm -q phpmailer || phpmailer --version

2. UPGRADE to newer than 5.2.13 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade phpmailer

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade phpmailer

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2015-8476?

debian linux: mitigate or apply the listed mitigation; phpmailer: upgrade to newer than 5.2.13. Exact commands for each OS are on this page.

Is CVE-2015-8476 being exploited?

CVE-2015-8476 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2015-8476 affect?

CVE-2015-8476 affects debian linux, phpmailer. Severity is medium (CVSS 5.0). Multiple CRLF injection vulnerabilities in PHPMailer before 5.2.14 allow attackers to inject arbitrary SMTP commands via CRLF sequences in an (1) email address to the validateAddress function in class.phpmailer.php or (2) SMTP command to th

How urgent is CVE-2015-8476?

Priority 43/100. On your watchlist

Software pages

PHP vulnerabilities · Debian vulnerabilities

Related CVEs

CVE-2023-42756 MEDIUM 4.4 UPGRADE MITIGATE A flaw was found in the Netfilter subsystem of the Linux kernel
CVE-2023-39417 HIGH 7.5 UPGRADE MITIGATE IN THE EXTENSION SCRIPT, a SQL Injection vulnerability was found in PostgreSQL if it uses @extowner@, @extsche
CVE-2026-111497 CRITICAL 9.8 EXPLOITED UPGRADE UPGRADE Google Brotli Unchecked Return Value Vulnerability
CVE-2025-38728 CRITICAL 9.1 UPGRADE MITIGATE In the Linux kernel, the following vulnerability has been resolved: smb3: fix for slab out of bounds on mount
CVE-2025-38204 HIGH 7.8 UPGRADE MITIGATE In the Linux kernel, the following vulnerability has been resolved: jfs: fix array-index-out-of-bounds read i

References

← Back to latest CVEs