Improper access control in Zimbra Collaboration - CVE-2026-50055
Published: August 21, 2026
Vulnerability identifier: #VU144524
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-50055
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to exfiltrate email.
The vulnerability exists due to improper access control in mail forwarding restrictions when forwarding mail despite restrictions being enabled. A remote user can bypass forwarding restrictions to exfiltrate email.
Exploitation requires mail forwarding restrictions to be enabled.
Affected software
Zimbra Collaboration
How to mitigate CVE-2026-50055
Install security update from vendor's website.
Zimbra Collaboration - update to 10.1.20