Main Vulnerability Database SB2026051936

SB2026051936 - Remote denial of service in Postfix

Published: May 19, 2026

Security Bulletin ID SB2026051936

CSH Severity

Medium

Patch available

YES

Number of vulnerabilities 1

Exploitation vector Remote access

Highest impact Denial of service

Breakdown by Severity

Low
Medium
High
Critical

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds read (CVE-ID: CVE-2026-43964)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to an out-of-bounds read in Postfix status code processing when handling enhanced status codes that are not followed by additional text. A remote attacker can supply a specially crafted response or input to cause a denial of service.

This is confirmed with an access(5) table and with a DNSBL server TXT response when Postfix is configured with "$rbl_code $rbl_text" in rbl_reply_maps or default_rbl_reply, and is likely reachable through a policy server response.

Remediation

Install update from vendor's website.

References

https://www.openwall.com/lists/oss-security/2026/05/04/30