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Critical 9.8Known exploited (CISA KEV)Published Dec 30, 2016
CVE-2016-10033The mailSend function in the 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 \" (ba…
Updated under an hour ago ()
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It affects phpmailer_project phpmailer and 2 other products. Add what you run to find out whether that includes you.
CISA lists it as known exploited since Jul 7, 2025; federal agencies had to remediate by Jul 28, 2025. Treat that date as your deadline.
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The mailSend function in the 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.
- CVSS
- 9.8 CRITICAL (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-88
- Known exploited
- Added to CISA KEV Jul 7, 2025; federal remediation due Jul 28, 2025Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- EPSS (exploitation in the next 30 days)
- 99.71% (percentile 100)
- Assigned by
- mitre
- NVD analysis
- Analyzed
- Record last updated
- Oct 21, 2025
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
phpmailer_project phpmailer phpmailer_project:phpmailer | before 5.2.18 | NVD |
wordpress wordpress wordpress:wordpress | through 4.7 | NVD |
joomla joomla! joomla:joomla! | from 1.5.0 through 3.6.5 | NVD |
References
- http://packetstormsecurity.com/files/140350/PHPMailer-Sendmail-Argument-Injection.htmlx-refsource-misc, exploit, third-party-advisory, vdb-entry
- https://www.drupal.org/psa-2016-004x-refsource-confirm, third-party-advisory
- https://www.exploit-db.com/exploits/42221/exploit, x-refsource-exploit-db, third-party-advisory, vdb-entry
- https://www.exploit-db.com/exploits/40969/exploit, x-refsource-exploit-db, third-party-advisory, vdb-entry
- https://www.exploit-db.com/exploits/41962/exploit, x-refsource-exploit-db, third-party-advisory, vdb-entry
- https://www.exploit-db.com/exploits/40968/exploit, x-refsource-exploit-db, patch, third-party-advisory, vdb-entry
- https://legalhackers.com/advisories/PHPMailer-Exploit-Remote-Code-Exec-CVE-2016-10033-Vuln.htmlx-refsource-misc, exploit, patch, third-party-advisory
- https://github.com/PHPMailer/PHPMailer/releases/tag/v5.2.18x-refsource-confirm, patch, vendor-advisory
- http://www.securityfocus.com/archive/1/539963/100/0/threadedmailing-list, x-refsource-bugtraq, broken-link, third-party-advisory, vdb-entry
- https://github.com/PHPMailer/PHPMailer/wiki/About-the-CVE-2016-10033-and-CVE-2016-10045-vulnerabilitiesx-refsource-confirm, patch, vendor-advisory
- http://packetstormsecurity.com/files/140291/PHPMailer-Remote-Code-Execution.htmlx-refsource-misc, exploit, third-party-advisory, vdb-entry
- https://www.exploit-db.com/exploits/40974/exploit, x-refsource-exploit-db, third-party-advisory, vdb-entry
- https://www.exploit-db.com/exploits/40986/exploit, x-refsource-exploit-db, third-party-advisory, vdb-entry
- https://www.exploit-db.com/exploits/40970/exploit, x-refsource-exploit-db, patch, third-party-advisory, vdb-entry
- http://www.rapid7.com/db/modules/exploit/multi/http/phpmailer_arg_injectionx-refsource-misc, exploit, third-party-advisory
- https://www.exploit-db.com/exploits/41996/exploit, x-refsource-exploit-db, third-party-advisory, vdb-entry
- http://seclists.org/fulldisclosure/2016/Dec/78mailing-list, x-refsource-fulldisc, patch, third-party-advisory
- http://www.securityfocus.com/bid/95108vdb-entry, x-refsource-bid, broken-link, exploit, third-party-advisory
- http://www.securitytracker.com/id/1037533vdb-entry, x-refsource-sectrack, broken-link, third-party-advisory
- https://developer.joomla.org/security-centre/668-20161205-phpmailer-security-advisory.htmlx-refsource-confirm, third-party-advisory
- https://www.exploit-db.com/exploits/42024/exploit, x-refsource-exploit-db, third-party-advisory, vdb-entry
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2016-10033us-government-resource
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.