Exim Vulnerability Allows Memory Disclosure in Certain Proxy Configurations
CVE-2026-48840

5.3MEDIUM

Key Information:

Vendor

Exim

Status
Exim
Vendor
CVE Published:
30 May 2026

What is CVE-2026-48840?

A vulnerability exists in Exim Mail Transfer Agent versions prior to 4.99.4. The issue arises in specific proxy configurations, where the software improperly handles certain short payloads. This oversight can lead to the disclosure of sensitive uninitialized stack memory values to connected clients, potentially compromising system integrity and security.

Affected Version(s)

Exim 4.88 < 4.99.4

References

https://exim.org/static/doc/security/EXIM-Security-2026-0...
https://www.openwall.com/lists/oss-security/2026/05/29/3

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.