Resource exhaustion in Dovecot and OX Dovecot Pro - CVE-2026-42006
Published: May 19, 2026
Vulnerability identifier: #VU131869
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-42006
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Dovecot
Affected software:
Dovecot
OX Dovecot Pro
Dovecot
OX Dovecot Pro
Detailed vulnerability description
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to uncontrolled resource consumption in imap-login when processing excessive bracing over IMAP. A remote user can send excessive bracing to cause a denial of service.
The issue remained reachable because an earlier fix blocked closing braces, but open braces could still bypass the limit.
How to mitigate CVE-2026-42006
Install security update from vendor's website.