Exim 4 before 4.94.2 has Improper Neutralization of Line Delimiters. An authenticated remote SMTP client can insert newline characters into a spool file (which indirectly leads to remote code execution as root) via AUTH= in a MAIL FROM command.
CVSS v4.0 Metrics
Exploitability
Attack VectorNetwork
ComplexityLow
RequirementsPresent
PrivilegesLow
User InteractionNone
Threat
Exploit MaturityPoC
Vulnerable System
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
Subsequent System
ConfidentialityNone
IntegrityNone
AvailabilityNone
Supplemental
SafetyNegligible
AutomatableYes
RecoveryAutomatic
Value DensityConcentrated
UrgencyMedium
Change Log
| Date | Source | Changes | Score |
|---|
| 2026-07-21 | PoC | E: U→P | 5.2 → 6.8 |
| 2026-07-21 | nvd | AV: P→N, AC: H→L, PR: H→L, UI: A→N, VC: N→H, VI: N→H, VA: N→H | 0.0 → 5.2 |
| 2026-07-21 | cve.org | initial, patch: Unavailable | 0.0 |
Affected Software
| Vendor | Product | Version |
|---|
| exim | exim | ≥ 4.00, < 4.94.2 |
Published: 2021-05-06