CVE-2026-40686
3.7
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Summary
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.
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Exim | Exim | 0 < 4.99.2 | affected |
Weaknesses
- CWE-125: CWE-125 Out-of-bounds Read
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: none
- Automatable: no
- Technical Impact: partial
References
- https://www.openwall.com/lists/oss-security/2026/04/30/21
- https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40686.assessment
- https://code.exim.org/exim/exim/commit/f2570bde16fb4d4a1242ff363a4c4eecf6372efc
- https://exim.org/static/doc/security/CVE-2026-40686.txt
Feedback
Was this page helpful?
Glad to hear it! Please tell us how we can improve.
Sorry to hear that. Please tell us how we can improve.