CVE-2025-61600 HIGH

CVE-2025-61600: Unbounded Memory Allocation in Stalwart IMAP parser

Vendor Stalwartlabs
Product stalwart
Weakness CWE-400
Published October 2, 2025
Last update October 3, 2025

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

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

What the vulnerability does

01Description

Stalwart is a mail and collaboration server. Versions 0.13.3 and below contain an unbounded memory allocation vulnerability in the IMAP protocol parser which allows remote attackers to exhaust server memory, potentially triggering the system's out-of-memory (OOM) killer and causing a denial of service. The CommandParser implementation enforces size limits on its dynamic buffer in most parsing states, but several state handlers omit these validation checks. This issue is fixed in version 0.13.4. A workaround for this issue is to implement rate limiting and connection monitoring at the network level, however this does not provide complete protection.

Key dates

02Disclosure timeline

October 2, 2025 CVE published
October 3, 2025 Record updated