---
id: "CVE-2026-125393"
page: "https://infrastack.ai/live/CVE-2026-125393"
kind: "vulnerability"
aliases: ["CVE-2026-125393"]
title: "MailEnable Enterprise Premium: IMAP heap overflow lets authenticated users crash mail service"
severity: "high"
cvss: 7.1
epss: null
exploited: false
status: "open"
category: "vendor"
products: []
ecosystems: []
tags: ["imap", "mailenable", "self-hosted", "vendor", "windows"]
not_affected_if: ["auth-required", "non-premium-edition"]
published_at: "2026-11-10T00:17:13+00:00"
first_seen_at: "2026-11-10T00:28:44+00:00"
updated_at: "2026-11-10T00:30:08+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-125393", "first_seen_at": "2026-11-10T00:28:44+00:00"}]
exploit_sources: []
---

# MailEnable Enterprise Premium: IMAP heap overflow lets authenticated users crash mail service

Link for people: https://infrastack.ai/live/CVE-2026-125393 (this .md is for agents)

MailEnable Enterprise Premium before 10.62 has a heap overflow in the IMAP X-FB-FETCH command, where an oversized X-FB-USER address is written past a fixed 0x400-byte buffer. An authenticated user can crash the IMAP service, causing denial of service.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed MailEnable Enterprise Premium version in the MailEnable administration console; unknown if the sources give another method.

## Fix

- MailEnable Enterprise Premium: move to `10.62` or later.

## Timeline

- 2026-11-10T00:28:44+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-125393

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/mailenable-enterprise-premium-before-10.62-heap-overflow-via-imap-x-fb-fetch

## From the sources

MailEnable Enterprise Premium before 10.62 contains a heap overflow vulnerability in the IMAP X-FB-FETCH command that allows authenticated users to overflow a fixed 0x400-byte heap buffer. Attackers can supply an X-FB-USER address longer than about 1016 bytes, which is formatted without a length check, to crash the IMAP service and cause denial of service.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_