Mimecast Email Security before 2020-01-10 allows any admin to spoof any domain, and pass DMARC alignment via SPF. This occurs through misuse of the address rewrite feature. (The domain being spoofed must be a customer in the Mimecast grid from which the spoofing occurs.)
CVSS v4.0 Metrics
Exploitability
Attack VectorNetwork
ComplexityLow
RequirementsPresent
PrivilegesHigh
User InteractionNone
Threat
Exploit MaturityUnreported
Vulnerable System
ConfidentialityNone
IntegrityHigh
AvailabilityNone
Subsequent System
ConfidentialityNone
IntegrityNone
AvailabilityNone
Supplemental
SafetyNegligible
AutomatableYes
RecoveryAutomatic
Value DensityConcentrated
UrgencyMedium
Change Log
| Date | Source | Changes | Score |
|---|
| 2026-07-21 | nvd | AV: P→N, AC: H→L, UI: A→N, VI: N→H | 0.0 → 2.1 |
| 2026-07-21 | cve.org | initial, patch: Unavailable | 0.0 |
Affected Software
| Vendor | Product | Version |
|---|
| mimecast | email_security | < 2020-01-10 |
Published: 2022-03-15
