---
id: CVE-2026-50055
title: >-
  A policy-enforcement flaw in Zimbra Collaboration Suite allows an
  authenticated user to bypass disabled mail forwarding by using a Sieve notify
  action to send copies of email content and headers to an arbitrary address.
summary: >-
  A policy-enforcement flaw in Zimbra Collaboration Suite allows an
  authenticated user to bypass disabled mail forwarding by using a Sieve notify
  action to send copies of email content and headers to an arbitrary address.
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-863
vendor: Zimbra
product: Zimbra Collaboration Suite
affected:
  - collaboration_suite < 10.1.20
published: '2026-10-08'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T20:49:23.240'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-50055'
references:
  - url: 'https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories'
    label: cve@rapid7.com
tags:
  - nvd
  - exploit-available
  - cve.org
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/HORKimhab/CVE-2026-50055'
  checkedAt: '2026-10-08T21:08:32.538Z'
exploitAvailable: true
ingestedAt: '2026-10-08T16:52:14.786Z'
---

## Overview

A policy-enforcement flaw in Zimbra Collaboration Suite allows an authenticated user to bypass disabled mail forwarding by using a Sieve notify action to send copies of email content and headers to an arbitrary address.

## Remediation

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