{"id":"GHSA-5f37-gxvh-23v6","aliases":["CVE-2016-10033"],"title":"Remote code execution in PHPMailer","titleSource":"OSV","descriptionSource":"OSV","declaredSeverity":"CRITICAL","description":"### Impact\nThe `mailSend` function in the default `isMail` transport in PHPMailer before 5.2.18 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 `Sender` property.\n\n### Patches\nFixed in 5.2.18\n\n### Workarounds\nFilter and validate user input before passing it to internal functions.\n\n### References\nhttps://nvd.nist.gov/vuln/detail/CVE-2016-10033\nRelated to a follow-on issue in https://nvd.nist.gov/vuln/detail/CVE-2016-10045\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open a private issue in [the PHPMailer project](https://github.com/PHPMailer/PHPMailer)","severity":"critical","score":9.8,"published":"2020-03-05T22:09:17.000Z","modified":"2025-10-22T19:26:42.172Z","withdrawn":false,"knownExploited":true,"affected":[{"ecosystem":"Packagist","name":"phpmailer/phpmailer","sources":[{"name":"OSV · GHSA-5f37-gxvh-23v6","url":"https://osv.dev/vulnerability/GHSA-5f37-gxvh-23v6"}],"ranges":[{"events":[{"introduced":"5.0.0"},{"fixed":"5.2.18"}],"type":"ECOSYSTEM"}],"versions":["v5.2.10","v5.2.11","v5.2.12","v5.2.13","v5.2.14","v5.2.15","v5.2.16","v5.2.17","v5.2.2","v5.2.4","v5.2.5","v5.2.6","v5.2.7","v5.2.8","v5.2.9"],"fixed":["5.2.18"]}],"sourceAffected":[],"references":["https://github.com/PHPMailer/PHPMailer/security/advisories/GHSA-5f37-gxvh-23v6","https://nvd.nist.gov/vuln/detail/CVE-2016-10033","https://www.exploit-db.com/exploits/42221","https://www.exploit-db.com/exploits/42024","https://www.exploit-db.com/exploits/41996","https://www.exploit-db.com/exploits/41962","https://www.exploit-db.com/exploits/40986","https://www.exploit-db.com/exploits/40974","https://www.exploit-db.com/exploits/40970","https://www.exploit-db.com/exploits/40969","https://www.exploit-db.com/exploits/40968","https://www.drupal.org/psa-2016-004","https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2016-10033","https://legalhackers.com/advisories/PHPMailer-Exploit-Remote-Code-Exec-CVE-2016-10033-Vuln.html","https://github.com/PHPMailer/PHPMailer/wiki/About-the-CVE-2016-10033-and-CVE-2016-10045-vulnerabilities","https://github.com/PHPMailer/PHPMailer/releases/tag/v5.2.18","https://github.com/PHPMailer/PHPMailer","https://github.com/FriendsOfPHP/security-advisories/blob/master/phpmailer/phpmailer/CVE-2016-10033.yaml","https://developer.joomla.org/security-centre/668-20161205-phpmailer-security-advisory.html","http://packetstormsecurity.com/files/140291/PHPMailer-Remote-Code-Execution.html","http://packetstormsecurity.com/files/140350/PHPMailer-Sendmail-Argument-Injection.html","http://seclists.org/fulldisclosure/2016/Dec/78","http://www.rapid7.com/db/modules/exploit/multi/http/phpmailer_arg_injection"],"sources":[{"name":"OSV","id":"GHSA-5f37-gxvh-23v6","modified":"2025-10-22T19:26:42.172992Z","url":"https://osv.dev/vulnerability/GHSA-5f37-gxvh-23v6"}],"assessments":[{"source":"OSV","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H","score":9.8}],"products":[],"remediation":[],"kev":{"status":"listed","checkedAt":"2026-10-29T01:35:32.302Z","cveID":"CVE-2016-10033","vendorProject":"PHP","product":"PHPMailer","vulnerabilityName":"PHPMailer Command Injection Vulnerability","dateAdded":"2025-07-07","shortDescription":"PHPMailer contains a command injection vulnerability because it fails to sanitize user-supplied input. Specifically, this issue affects the 'mail()' function of 'class.phpmailer.php' script. An attacker can exploit this issue to execute arbitrary code within the context of the application. Failed exploit attempts will result in a denial-of-service condition.","requiredAction":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.","dueDate":"2025-07-28","knownRansomwareCampaignUse":"Unknown","forensicTriage":"No","notes":"This vulnerability could affect an open-source component, third-party library, protocol, or proprietary implementation that could be used by different products. For more information, please see: https://github.com/PHPMailer/PHPMailer/releases/tag/v5.2.18 ; https://github.com/advisories/GHSA-5f37-gxvh-23v6 ; https://nvd.nist.gov/vuln/detail/CVE-2016-10033","cwes":["CWE-77","CWE-88"]},"coverage":[{"source":"NVD","status":"available","checkedAt":"2026-10-28T08:55:34.641Z","attemptedAt":"2026-10-28T08:55:34.641Z"},{"source":"GHSA","status":"refresh-failed","attemptedAt":"2026-10-28T08:55:32.875Z"},{"source":"EUVD","status":"available","checkedAt":"2026-10-28T08:55:33.485Z","attemptedAt":"2026-10-28T08:55:33.485Z"},{"source":"EPSS","status":"available","checkedAt":"2026-10-28T08:55:34.164Z","attemptedAt":"2026-10-28T08:55:34.164Z"}],"evidence":[{"source":"ENISA EUVD","id":"EUVD-2020-0331","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2020-0331","modified":"Oct 21, 2025, 11:55:47 PM","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","checkedAt":"2026-10-28T08:55:33.485Z"},{"source":"FIRST EPSS","id":"CVE-2016-10033","url":"https://www.first.org/epss/","probability":0.99714,"percentile":0.99952,"date":"2026-10-27","checkedAt":"2026-10-28T08:55:34.164Z"},{"source":"NVD","id":"CVE-2016-10033","url":"https://nvd.nist.gov/vuln/detail/CVE-2016-10033","modified":"2026-06-17T00:38:55.477","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","checkedAt":"2026-10-28T08:55:34.641Z"},{"source":"NVD","id":"CVE-2016-10033","url":"https://nvd.nist.gov/vuln/detail/CVE-2016-10033","modified":"2026-06-17T00:38:55.477","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","checkedAt":"2026-10-28T08:55:34.641Z"},{"source":"NVD","id":"CVE-2016-10033","url":"https://nvd.nist.gov/vuln/detail/CVE-2016-10033","modified":"2026-06-17T00:38:55.477","score":7.5,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:P","checkedAt":"2026-10-28T08:55:34.641Z"},{"source":"Exploit-DB","id":"41962","url":"https://www.exploit-db.com/exploits/41962","checkedAt":"2026-10-29T00:00:35.338Z"},{"source":"Exploit-DB","id":"41996","url":"https://www.exploit-db.com/exploits/41996","checkedAt":"2026-10-29T00:00:35.338Z"},{"source":"Exploit-DB","id":"42024","url":"https://www.exploit-db.com/exploits/42024","checkedAt":"2026-10-29T00:00:35.338Z"},{"source":"Exploit-DB","id":"40968","url":"https://www.exploit-db.com/exploits/40968","checkedAt":"2026-10-29T00:00:35.338Z"},{"source":"Exploit-DB","id":"40970","url":"https://www.exploit-db.com/exploits/40970","checkedAt":"2026-10-29T00:00:35.338Z"},{"source":"Exploit-DB","id":"40974","url":"https://www.exploit-db.com/exploits/40974","checkedAt":"2026-10-29T00:00:35.338Z"},{"source":"Exploit-DB","id":"40969","url":"https://www.exploit-db.com/exploits/40969","checkedAt":"2026-10-29T00:00:35.338Z"},{"source":"Exploit-DB","id":"40986","url":"https://www.exploit-db.com/exploits/40986","checkedAt":"2026-10-29T00:00:35.338Z"},{"source":"Exploit-DB","id":"42221","url":"https://www.exploit-db.com/exploits/42221","checkedAt":"2026-10-29T00:00:35.338Z"}]}