WS-2026-0068
Published:September 07, 2026
Updated:September 10, 2026
Postfix SMTP server null pointer read denial of service. With smtputf8_enable = yes (the default) and strict_smtputf8 = yes (not the default), a VRFY command carrying a non-ASCII address without the SMTPUTF8 parameter called mail_reset() in vrfy_cmd(), resetting MAIL FROM state without resetting RCPT TO state. A crafted remote SMTP client could then send DATA and crash the Postfix SMTP server process with a null pointer read. Fixed by removing the mail_reset() call from vrfy_cmd() in src/smtpd/smtpd.c.
Affected Packages
https://github.com/vdukhovni/postfix.git (GITHUB):
Affected version(s) >=v3.8.0 <v3.8.21Fix Suggestion:
Update to version v3.8.21https://github.com/vdukhovni/postfix.git (GITHUB):
Affected version(s) >=v3.10.0 <v3.10.14Fix Suggestion:
Update to version v3.10.14https://github.com/vdukhovni/postfix.git (GITHUB):
Affected version(s) >=v3.11.0 <v3.11.7Fix Suggestion:
Update to version v3.11.7https://github.com/vdukhovni/postfix.git (GITHUB):
Affected version(s) >=v3.7.0 <v3.7.23Fix Suggestion:
Update to version v3.7.23https://github.com/vdukhovni/postfix.git (GITHUB):
Affected version(s) >=v3.6.0 <v3.6.21Fix Suggestion:
Update to version v3.6.21https://github.com/vdukhovni/postfix.git (GITHUB):
Affected version(s) >=v3.9.0 <v3.9.15Fix Suggestion:
Update to version v3.9.15https://github.com/vdukhovni/postfix.git (GITHUB):
Affected version(s) >=v3.0.0 <v3.5.28Fix Suggestion:
Update to version v3.5.28Related Resources (2)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.2
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.9
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
NULL Pointer Dereference