CVE-2026-40684 MEDIUM

CVE-2026-40684

Vendor Exim
Product Exim
Weakness CWE-684
Published April 30, 2026
Last update May 1, 2026
View on NVD All CVEs

CVSS base score

5.9/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

What the vulnerability does

01Description

In Exim before 4.99.2, on systems using musl libc (not glibc), an attacker can crash the connection instance when malformed DNS data is present in PTR records. This is caused by a dn_expand oddity in octal printing.

Key dates

02Disclosure timeline

April 30, 2026 CVE published
May 1, 2026 Record updated