CVE-2021-34551 json
Remote Code Execution vulnerability in PHPMailer 6.4.1 running on Windows
published 2021-06-16 5 y ago modified 2026-09-08 2 mo ago also BIT-phpmailer-2021-34551 , EUVD-2021-1283 , GHSA-7q44-r25x-wm4q
- cvss
- 8.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.8%
- EPSS 2.8% chance of exploitation in 30 days, percentile 86%
- public exploits
- 0
- none known
Summary
PHPMailer before 6.5.0 on Windows allows remote code execution if lang_path is untrusted data and has a UNC pathname.
Patch / fix
- packagist phpmailer/phpmailer 6.5.0
- bitnami phpmailer 6.5.0
- phpmailer_project phpmailer 6.5.0
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2021-34551 updated cvss 9.8
phpmailer: remote code execution if lang_path is untrusted data and has a UNC pathname
-
Red Hat All currently supported Red Hat productsnot affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
Exploit prediction
2.80% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| GitHub | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 5.1 | AV:N/AC:H/Au:N/C:P/I:P/A:P |
| OSV | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| packagist | phpmailer/phpmailer | <6.5.0 |
6.5.0 |
| bitnami | phpmailer | <6.5.0 |
6.5.0 |
Classification
References
-
github.com
/PHPMailer/PHPMailer/commit/acd264bf17ff4ac5c915f0d4226dce8a9ea70bc3
web
-
lists.fedoraproject.org
/archives/list/package-announce%40lists.fedoraproject.org/message/FJYSOFCUBS67J3TKR74SD3C454N7VTYM/
vendor-advisory, web
-
lists.fedoraproject.org
/archives/list/package-announce%40lists.fedoraproject.org/message/3YRMWGA4VTMXFB22KICMB7YMFZNFV3EJ/
vendor-advisory, web
-
github.com
/PHPMailer/PHPMailer/blob/master/SECURITY.md
web, issue-tracking, third-party-advisory, advisory
-
github.com
/PHPMailer/PHPMailer/security/advisories/GHSA-7q44-r25x-wm4q
web
-
nvd.nist.gov
/vuln/detail/CVE-2021-34551
advisory, web
-
github.com
/FriendsOfPHP/security-advisories/blob/master/phpmailer/phpmailer/CVE-2021-34551.yaml
web
-
github.com
/PHPMailer/PHPMailer/releases/tag/v6.5.0
web
-
lists.fedoraproject.org
/archives/list/package-announce@lists.fedoraproject.org/message/3YRMWGA4VTMXFB22KICMB7YMFZNFV3EJ
web
-
lists.fedoraproject.org
/archives/list/package-announce@lists.fedoraproject.org/message/FJYSOFCUBS67J3TKR74SD3C454N7VTYM
web
Sources
- CVE List CVE-2021-34551
- GitHub Advisory GHSA-7q44-r25x-wm4q
- NVD CVE-2021-34551
- OSV BIT-phpmailer-2021-34551
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