CVE-2026-93639

A missing authorization vulnerability in Zimbra Collaboration Suite (ZCS) allows a delegated administrator with no explicit administrative grants to overwrite global Zimlet configuration through ConfigureZimletRequest. The uploaded configuration can also add an attacker-controlled domain to the proxy allowlist of the default class of service. If a signed-in user in that class opens a crafted /service/proxy URL, Zimbra serves attacker-controlled HTML under its own origin. The resulting JavaScript can read mailbox data and perform authenticated actions as the victim. Exploitation requires a delegated-administrator account and access to the admin SOAP service; the browser compromise additionally requires the victim to open the crafted URL. ZCS 10.1.16 and 10.1.20 are affected.

CVSS v3 8.7 HIGH

8.7^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.3 / Impact : 5.8

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
https://www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1/

Configurations

No configuration.

History

23 Oct 2026, 14:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-23 14:17

Updated : 2026-10-28 20:18

NVD link : CVE-2026-93639

Mitre link : CVE-2026-93639

CVE.ORG link : CVE-2026-93639

JSON object : View

Products Affected

No product.

CWE

CWE-862

Missing Authorization

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