CVE-2026-93639 Zimbra Collaboration Suite - Broken Access Control & Stored XSS

Zimbra Collaboration Suite (ZCS) 10.1.16 and 10.1.20 contain a broken access control caused by missing authorization in ConfigureZimletRequest, letting delegated administrators overwrite global Zimlet configuration and execute attacker-controlled scripts via crafted proxy URLs, exploit requires delegated-administrator account and victim interaction.

CVSS base score 8.7 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Required
EPSS
0.36% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Broken Access Control
Impact
Stored XSS, Broken Access Control, Information Disclosure
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
Published
23 October 2026
Updated
25 October 2026
Weakness
CWE-862

Vendor fix

Update to a version later than 10.1.20 or latest available version.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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