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.
An official patch is available. Apply the patch as soon as possible.
Consider disconnecting the vulnerable system from the internet until a fix is applied.
CVSS v4.0 Metrics
Exploitability
Attack VectorNetwork
ComplexityLow
RequirementsPresent
PrivilegesNone
User InteractionNone
Threat
Exploit MaturityAttacked
Vulnerable System
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
Subsequent System
ConfidentialityNone
IntegrityNone
AvailabilityNone
Supplemental
SafetyNegligible
AutomatableYes
RecoveryAutomatic
Value DensityConcentrated
UrgencyMedium
Patch StatusOfficial Patch
Change Log
| Date | Source | Changes | Score |
|---|
| 2026-07-21 | cisa | E: U→A | 7.2 → 9.2 |
| 2026-07-21 | nvd | patch: Unavailable→Official Patch | 7.2 → 7.2 |
| 2026-07-21 | cve.org | initial, patch: Unavailable | 7.2 |
Affected Software
| Vendor | Product | Version |
|---|
| joomla | joomla\! | ≥ 1.5.0, ≤ 3.6.5 |
| phpmailer_project | phpmailer | < 5.2.18 |
| wordpress | wordpress | ≤ 4.7 |
Published: 2016-12-30
