Description

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.

INFO

Published Date :

2026-04-30T00:00:00.000Z

Last Modified :

2026-05-01T17:22:32.062Z

Source :

mitre
AFFECTED PRODUCTS

The following products are affected by CVE-2026-40684 vulnerability.

Vendors Products
Exim
  • Exim
REFERENCES

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-40684.

URL Resource
http://www.openwall.com/lists/oss-security/2026/05/01/11 cve-icon
https://code.exim.org/exim/exim/commit/628bbaca7672748d941a12e7cd5f0122a4e18c81 cve-icon cve-icon
https://exim.org/static/doc/security/CVE-2026-40684.txt cve-icon cve-icon
https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40684.assessment cve-icon cve-icon
https://www.openwall.com/lists/oss-security/2026/04/30/21 cve-icon cve-icon
Login to claim this CVE

CVSS Vulnerability Scoring System

Detailed values of each vector for above chart.
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact