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CVE Vulnerability Details :
CVE-2026-40686
PUBLISHED
More InfoOfficial Page
Assigner-mitre
Assigner Org ID-8254265b-2729-46b6-b9e3-3dfca2d5bfca
View Known Exploited Vulnerability (KEV) details
Published At-30 Apr, 2026 | 00:00
Updated At-01 May, 2026 | 14:27
Rejected At-
▼CVE Numbering Authority (CNA)

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 Products
Vendor
EximExim
Product
Exim
Default Status
unaffected
Versions
Affected
  • From 0 before 4.99.2 (semver)
Problem Types
TypeCWE IDDescription
CWECWE-125CWE-125 Out-of-bounds Read
Type: CWE
CWE ID: CWE-125
Description: CWE-125 Out-of-bounds Read
Metrics
VersionBase scoreBase severityVector
3.13.7LOW
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Version: 3.1
Base score: 3.7
Base severity: LOW
Vector:
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions
Configurations
Workarounds
Exploits
Credits
Timeline
EventDate
Replaced By
Rejected Reason
References
HyperlinkResource
https://www.openwall.com/lists/oss-security/2026/04/30/21
N/A
https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40686.assessment
N/A
https://code.exim.org/exim/exim/commit/f2570bde16fb4d4a1242ff363a4c4eecf6372efc
N/A
https://exim.org/static/doc/security/CVE-2026-40686.txt
N/A
Hyperlink: https://www.openwall.com/lists/oss-security/2026/04/30/21
Resource: N/A
Hyperlink: https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40686.assessment
Resource: N/A
Hyperlink: https://code.exim.org/exim/exim/commit/f2570bde16fb4d4a1242ff363a4c4eecf6372efc
Resource: N/A
Hyperlink: https://exim.org/static/doc/security/CVE-2026-40686.txt
Resource: N/A
▼Authorized Data Publishers (ADP)
CISA ADP Vulnrichment
Affected Products
Metrics
VersionBase scoreBase severityVector
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions
Configurations
Workarounds
Exploits
Credits
Timeline
EventDate
Replaced By
Rejected Reason
References
HyperlinkResource
Details not found