Skip to main content
VulnerabilityPublished

CVE-2026-40020: Open-Xchange OX Dovecot Pro · Improper Access Control

Affects Open-Xchange OX Dovecot ProSource CVE Database V5

0
Compare

Not known to be exploited · CVSS 3.1 Low.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score
3.1Low
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.2% chance of exploitation in 30 days – higher than 17% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 12 May 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
Open-Xchange GmbHOX Dovecot ProAffected
  • <=2.3.0
Fixed in–

AI-suggested

The vendor advisory does not specify an official patch or remediation level. Users should monitor vendor communications for updates and apply any forthcoming patches promptly. Since the vulnerability requires the IMAP SETACL command and specific conditions, restricting access to IMAP services and reviewing ACL configurations may reduce exposure.

Description

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.

References

Community reviews

Loading reviews…