GHSA-pr44-4jfr-286m — swiftmailer/swiftmailer
CRITICALGHSA-pr44-4jfr-286m is a critical-severity (CVSS 9.8) CWE-77 vulnerability in swiftmailer/swiftmailer. 7 public exploit references exist, so weaponization risk is real. A fix is available for swiftmailer/swiftmailer — see the affected versions and patch details below.
Swift Mailer mail transport Command Injection
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.
How urgent is this, really
GHSA-pr44-4jfr-286m plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 376,715 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
swiftmailer/swiftmailerReal-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
The mail transport (aka Swift_Transport_MailTransport) in Swift Mailer before 5.4.5 might allow remote attackers to pass extra parameters to the mail command and consequently execute arbitrary code via a " (backslash double quote) in a crafted e-mail address in the (1) From, (2) ReturnPath, or (3) Sender header.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | swiftmailer/swiftmailer | all versions | 5.4.5composer require swiftmailer/swiftmailer:^5.4.5 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
PHPMailer < 5.2.20 with Exim MTA - Remote Code Execution
by phackt_ul · Jun 21, 2017
SwiftMailer < 5.4.5-DEV - Remote Code Execution
by Dawid Golunski · Dec 28, 2016
PHPMailer < 5.2.20 / SwiftMailer < 5.4.5-DEV / Zend Framework / zend-mail < 2.4.11 - 'AIO' 'PwnScriptum' Remote Code Execution
by Dawid Golunski · Jan 2, 2017
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for swiftmailer/swiftmailer, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update swiftmailer/swiftmailer to 5.4.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pr44-4jfr-286m 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 GHSA-pr44-4jfr-286m can be triaged on real exposure rather than presence alone.
Tailored to GHSA-pr44-4jfr-286m. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-pr44-4jfr-286m in your dependencies?
O3 Security finds GHSA-pr44-4jfr-286m across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.