Threats Tagged 'cve-2026-42006'

CVE-2026-42006 is a vulnerability in the Dovecot IMAP server that allows an attacker to cause uncontrolled memory usage by sending excessive bracing characters over IMAP. The previous fix for a related issue was incomplete, leaving a bypass via open braces. This can lead to memory consumption up to the configured memory limit, resulting in a denial of service. No public exploits are known. Red Hat has released security updates addressing this issue for multiple versions of Red Hat Enterprise Linux and related products.

An attacker can cause uncontrolled memory usage with excessive bracing over IMAP. The fix in CVE-2026-27857 was incomplete, only blocking one way of doing this, so there was still another way left open. In particular, the fix was for closing braces, but you could still use open braces to bypass the limit. Using excessive bracing, attacker can cause memory usage up to configured memory limit. Install fixed version, or configure vsz_limit for imap process to low value. No publicly available exploits are known.