PHPMailer before 6.5.0 on Windows allows remote code execution if lang_path is untrusted data and has a UNC pathname.
Priority MEDIUM 40CWE-434Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-434.
Summary
PHPMailer before 6.5.0 on Windows allows remote code execution if lang_path is untrusted data and has a UNC pathname.
Why it matters now
EPSS 0.02803 86th percentileScored 2026-11-07
Fix Fixed phpmailer/phpmailer (Packagist): 6.5.0
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
| — | phpmailer/phpmailer (Packagist) | before 6.5.0 | 6.5.0 | Patch available | GHSA-7q44-r25x-wm4q |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- phpmailer/phpmailer (Packagist) Vendor— Affected before 6.5.0 Fixed in 6.5.0 Patch available GHSA-7q44-r25x-wm4q
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:phpmailer_project:phpmailer:*:*:*:*:*:*:*:* | before 6.5.0 | Vulnerable | Phpmailer Project |
| cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Microsoft |
| cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* | 33 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* | 34 | Vulnerable | Fedoraproject |
- cpe:2.3:a:phpmailer_project:phpmailer:*:*:*:*:*:*:*:* Versions before 6.5.0 Vulnerable ·Phpmailer Project
- cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Microsoft
- cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* Versions 33 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:* Versions 34 Vulnerable ·Fedoraproject
Remediation
- Fix · GHSA-7q44-r25x-wm4q phpmailer/phpmailer (Packagist) Fixed in 6.5.0 Advisory →
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2021-34551
- 2026-10-03 Alias added: GHSA-7q44-r25x-wm4q
References
Advisory 4
Other 6
- https://github.com/PHPMailer/PHPMailer/security/advisories/GHSA-7q44-r25x-wm4q
- https://github.com/PHPMailer/PHPMailer/commit/acd264bf17ff4ac5c915f0d4226dce8a9ea70bc3
- https://github.com/FriendsOfPHP/security-advisories/blob/master/phpmailer/phpmailer/CVE-2021-34551.yaml
- https://github.com/PHPMailer/PHPMailer/releases/tag/v6.5.0
- https://lists.fedoraproject.org/archives/list/[email protected]/message/3YRMWGA4VTMXFB22KICMB7YMFZNFV3EJ
- https://lists.fedoraproject.org/archives/list/[email protected]/message/FJYSOFCUBS67J3TKR74SD3C454N7VTYM
Sources
- CVE-2021-34551 · CVE Program
- CVE-2021-34551 · NVD
- FIRST EPSS
- GHSA-7q44-r25x-wm4q · GitHub Advisory Database · CC BY 4.0
- CVE-2021-34551 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences