CVE-2026-40686
CVSS Score
3.7
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-125 |
| Vendor | exim |
| Product | exim |
| Published | Apr 30, 2026 |
| Last Updated | Apr 30, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Affected Versions
Exim / Exim
0 < 4.99.2
References
exim.org: https://exim.org/static/doc/security/CVE-2025-40686.txt openwall.com: https://www.openwall.com/lists/oss-security/2026/04/30/21 exim.org: https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40686.assessment code.exim.org: https://code.exim.org/exim/exim/commit/f2570bde16fb4d4a1242ff363a4c4eecf6372efc