CVE-2006-5734 — phpmailer/phpmailer
CVE-2006-5734 is a security vulnerability in phpmailer/phpmailer. A fix is available for phpmailer/phpmailer — see the affected versions and patch details below.
PHPMailer Local file inclusion
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
phpmailer/phpmailerReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Impact
Arbitrary local file inclusion via the $lang property, remotely exploitable if host application passes unfiltered user data into that property. The 3 CVEs listed are applications that used PHPMailer that were vulnerable to this problem.
Patches
It's not known exactly when this was fixed in the host applications, but it was fixed in PHPMailer 5.2.0.
Workarounds
Filter and validate user-supplied data before use.
References
https://nvd.nist.gov/vuln/detail/CVE-2006-5734 https://nvd.nist.gov/vuln/detail/CVE-2007-3215 https://nvd.nist.gov/vuln/detail/CVE-2007-2021 Example exploit: https://www.exploit-db.com/exploits/14893
For more information
If you have any questions or comments about this advisory:
- Open a private issue in the PHPMailer project
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | phpmailer/phpmailer | all versions | 5.2.0composer require phpmailer/phpmailer:^5.2.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for phpmailer/phpmailer, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update phpmailer/phpmailer to 5.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2006-5734 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2006-5734 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2006-5734. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2006-5734 in your dependencies?
O3 Security finds CVE-2006-5734 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.