CVE-2026-40020
LOW severity · CVSS 3.1 · Improper access control
3.1CVSS LOW
Summary
Attacker can use the IMAP SETACL command to inject the anyone permission to user's dovecot-acl file even if imap_acl_allow_anyone=no. This causes folders to be spammed to all users. The impact is limited to being able to spam folders to other users, no unexpected access is gained. Install to fixed version. No publicly available exploits are known.
Impact & exploitability
Attack vectorNetwork
Attack complexityHigh
Privileges requiredLow
User interactionNone
Confidentiality impactNone
Integrity impactNone
Availability impactLow
Exploit probability (EPSS)0%
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
Affected products we track (1)
Recommendation
Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.