Medium severity · published Aug 28, 2026
CVE-2026-42392
An attacker that has valid credentials can send an invalid IMAP URLFETCH command, which causes uninitialized memory to be included in the error response returned to the client
4.3
CVSS
0.3%
EPSS
No
On KEV
Description
An attacker that has valid credentials can send an invalid IMAP URLFETCH command, which causes uninitialized memory to be included in the error response returned to the client. Process memory contents can be disclosed to the client, which may include sensitive data. Disable the IMAP URLAUTH functionality. Update to non-vulnerable version. No publicly available exploits are known.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 19% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OD
OX Dovecot CE · Open-Xchange GmbH
2.3.0 before 2.4.5 · source: vendor
OD
OX Dovecot Pro · Open-Xchange GmbH
2.3.0 before 3.1.6 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42392
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-42392
documentation.open-xchange.com
https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json
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