Description

In Exim before 4.99.2, when utf8 operators are enabled, there is an out-of-bounds read if large UTF-8 trailing characters are present (malformed UTF-8 header data). Information might be divulged within an error message produced during handling of an unrelated e-mail message.

INFO

Published Date :

2026-04-30T00:00:00.000Z

Last Modified :

2026-05-01T14:27:11.390Z

Source :

mitre
AFFECTED PRODUCTS

The following products are affected by CVE-2026-40686 vulnerability.

Vendors Products
Exim
  • Exim
REFERENCES

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-40686.

URL Resource
https://code.exim.org/exim/exim/commit/f2570bde16fb4d4a1242ff363a4c4eecf6372efc cve-icon cve-icon
https://exim.org/static/doc/security/CVE-2026-40686.txt cve-icon cve-icon
https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40686.assessment cve-icon cve-icon
https://www.openwall.com/lists/oss-security/2026/04/30/21 cve-icon cve-icon
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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