CVE-2026-27852 — HIGH (7.5)

Vulnerability Description

An attacker that can send mail to a user can craft a message whose headers contain a very large number of email addresses or MIME parameters, which causes excessive memory usage when the message is later parsed. The message is still delivered, but reading it over IMAP can exhaust the memory limit of the process and terminate it, causing denial of service for the affected user. Update to non-vulnerable version. No publicly available exploits are known.

CVSS Score

7.5

HIGH

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

NONE

Availability

HIGH

Related Weaknesses (CWE)

CWE-400

References

https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxd

FAQ

What is CVE-2026-27852?

CVE-2026-27852 is a vulnerability with a CVSS score of 7.5 (HIGH). An attacker that can send mail to a user can craft a message whose headers contain a very large number of email addresses or MIME parameters, which causes excessive memory usage when the message is la...

How severe is CVE-2026-27852?

CVE-2026-27852 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-27852?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.