CVE-2026-40686CWE-125

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…

Low · published April 30, 2026

CVSS v3.1
3.7
EPSS
0%
Percentile
33.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
3.7 · LOW
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00404 · 33.5th percentile
Weakness
CWE-125 · Out-of-bounds Read
Published
2026-04-30T00:00Z
EPSS history
Timeline
  • 30 APR 00:00Z
    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…
    cvelistv5