CVE-2026-40686

Published: Mag 01, 2026 Last Modified: Mag 01, 2026
ExploitDB:
Other exploit source:
Google Dorks:
LOW 3,7
Attack Vector: network
Attack Complexity: high
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: low
Integrity: none
Availability: none

Description

AI Translation Available

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.

EPSS (Exploit Prediction Scoring System)

Trend Analysis

EPSS (Exploit Prediction Scoring System)

Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.

EPSS Score
0,0003
Percentile
0,1th
Updated

Single Data Point

Only one EPSS measurement is available for this CVE. Trend analysis requires multiple data points over time.

125

Out-of-bounds Read

Draft
Common Consequences
Security Scopes Affected:
Confidentiality Availability Other
Potential Impacts:
Read Memory Bypass Protection Mechanism Dos: Crash, Exit, Or Restart Varies By Context
Applicable Platforms
Languages: C, C++, Memory-Unsafe
Technologies: ICS/OT
View CWE Details
Application

Exim by Exim

Version Range Affected
To 4.99.2 (exclusive)
cpe:2.3:a:exim:exim:*:*:*:*:*:*:*:*
Common Platform Enumeration - Standardized vulnerability identification
https://code.exim.org/exim/exim/commit/f2570bde16fb4d4a1242ff363a4c4eecf6372efc
https://exim.org/static/doc/security/cve-2026-04.1/CVE2026-40686.assessment
https://exim.org/static/doc/security/CVE-2026-40686.txt
https://www.openwall.com/lists/oss-security/2026/04/30/21