Out-of-bounds Read Affecting exim package, versions <4.99.5-r0


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.4% (32nd percentile)

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  • Snyk IDSNYK-WOLFILATEST-EXIM-18968041
  • published19 Aug 2026
  • disclosed30 Apr 2026

Introduced: 30 Apr 2026

CVE-2026-40686  (opens in a new tab)
CWE-125  (opens in a new tab)

How to fix?

Upgrade Wolfi exim to version 4.99.5-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream exim package and not the exim package as distributed by Wolfi. See How to fix? for Wolfi relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1