CVE-2026-40687

State: Published
Severity: 4.8 Medium
Published: Apr 30, 2026
Updated: May 1, 2026
Reserved: Apr 14, 2026

Description

In Exim before 4.99.2, when the SPA authentication driver is used with an adversarial SPA resource, there can be an out-of-bounds write that crashes the connection instance, or erroneous data processing that divulges data from uninitialized heap memory.

Scores

CVSS	Score	Vector	Source
3.1	4.8 Medium	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L	mitre

Weaknesses

CWE-909 Missing Initialization of Resource

Affected Products

Product	Versions
EximExim	before 4.99.2Affected

References

https://www.openwall.com/lists/oss-security/2026/04/30/21
https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40687.assessment
https://code.exim.org/exim/exim/commit/68b963b9f75ca27b38e1c0f8c87037990199f505
https://exim.org/static/doc/security/CVE-2026-40687.txt

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