CVE-2026-94056: High severity Exim Exim vulnerability
Exim before 4.100.1, when Proxy-Protocol is used with an attacker-controlled proxy, allows attackers to read certain uninitialized data from stack memory.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/exim4to a version that resolves this vulnerability.Fixed in 4.98.2-1+deb13u5Fixed in 4.100.1-1Fixed in 4.100.1-2 - Upgrade
Upgrade
Eximto a version that resolves this vulnerability.Fixed in 4.100.1
Event History
Frequently Asked Questions
Which deployments are exposed?
Exim deployments using Proxy-Protocol with an attacker-controlled proxy are exposed. The issue affects Exim versions before 4.100.1.
What does an attacker need to exploit this?
The attacker needs network access and an attacker-controlled proxy participating in Proxy-Protocol handling. No privileges or user interaction are required, although exploitation has high attack complexity.
What is the impact?
An attacker may read certain uninitialized data from Exim stack memory. The listed impact includes high confidentiality impact and low availability impact, with no integrity impact.