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Vulnerability record · CVE-2026-40687 · published 30 April 2026

CVE-2026-40687: Exim vulnerability

Exim · Exim

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.

9.1 CVSS 3.1 Critical EPSS 0.67% · top 49.9% CWE-909 · CWE-909
9.1CVSS 3.1 base score
0.67%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References
17 Jun 2026Last modified by NVD

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.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://code.exim.org/exim/exim/commit/68b963b9f75ca27b38e1c0f8c87037990199f505 Patch
https://exim.org/static/doc/security/CVE-2026-40687.txt Broken Link
https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40687.assessment Vendor Advisory
https://www.openwall.com/lists/oss-security/2026/04/30/21 Mailing ListThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-40687), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.