CVE-2026-40020

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.

CVSS 3.1

4.3CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

EPSS

0.3% chance of exploitation in the next 30 days; higher than 17% of CVEs (scores of 2026-10-26)

CWE

CWE-284

Published

2026-05-12

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

Affected

• dovecot:dovecot
• open-xchange:dovecot

References

• https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0002.json

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