CVE-2026-94054
Description
A flaw was found in Exim. When the Proxy-Protocol is used with an attacker-controlled proxy, a remote attacker could exploit an out-of-bounds write vulnerability. This could lead to data corruption, denial of service, or potentially arbitrary code execution, allowing the attacker to execute malicious code on the system.
Statement
Red Hat Product Security has determined that this vulnerability does not affect any currently supported Red Hat product. This assessment may evolve based on further analysis and discovery. For more information about this vulnerability and the products it affects, please see the linked references.
Mitigation
To mitigate this vulnerability, disable the Proxy-Protocol feature in Exim if it is not essential for your deployment. If Proxy-Protocol is required, restrict Exim to accept connections only from trusted proxy servers. Consult Exim documentation for configuration instructions. A restart of the Exim service is necessary for these changes to apply.
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
Frequently Asked Questions
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