---
id: CVE-2025-61600
title: Stalwart is a mail and collaboration server
summary: >-
  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
  sy…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-400
  - CWE-789
published: '2025-10-02'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T23:10:00.213'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-61600'
references:
  - url: >-
      https://github.com/stalwartlabs/stalwart/commit/a8e631e881bded8128358732f18e02ca94a4e677
    label: security-advisories@github.com
  - url: 'https://github.com/stalwartlabs/stalwart/releases/tag/v0.13.4'
    label: security-advisories@github.com
  - url: >-
      https://github.com/stalwartlabs/stalwart/security/advisories/GHSA-8jqj-qj5p-v5rr
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00562
epssPercentile: 0.4499
ingestedAt: '2026-10-08T23:16:47.361Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.