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CVE-2016-10033

The mailSend function in the isMail transport in PHPMailer before 5.2.18 might allow remote attackers to pass extra parameters to the mail…

Critical9.8Known exploitedEPSS 99.7%
Published
Updated
Reserved
Assigned by
mitre

Description

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.

Exploited in the wild

CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as PHPMailer Command Injection Vulnerability.

Added
7 Jul 2025
Fix due (US federal)
28 Jul 2025
Used by ransomware
Not known

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Scores

CVSS scores of CVE-2016-10033, by who scored it
Scored byCVSSScoreVector
CISA-ADPADP (enrichment)3.1Critical9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVDNVD · Analyzed3.1Critical9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (exploitation in 30 days)
99.7% · top 0.1% of all CVEs (2 Nov 2026)
CISA SSVC
Exploitation: active · Automatable: yes · Technical impact: total

Loading the EPSS history…

The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.

Weakness

Affected products

  • n/a

    • affected n/a

Affected packages

From reviewed advisories of the GitHub Advisory Database.

References (22)

Sources

The same CVE in the primary databases and aggregators, to check against.

Record last updated .