Vulnerability in Synacor Zimbra Collaboration Suite

CVE-2026-73576

In Zimbra Collaboration (ZCS) before 10.1.17, weak cryptographic key generation vulnerability exists in the OnlyOffice integration. The zimbraDocumentEditingJwtSecret is generated using an insecure random number generator, resulting in insufficient entropy. An attacker who obtains a JWT signed with the generated secret may be able to recover the JWT signing secret through offline brute-force, potentially enabling JWT forgery.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:H/A:N.

EPSS exploit prediction

EPSS 0.003, 26.8th percentile (scored ); unchanged over 30 days. About EPSS.

Affected products

Weakness classification (CWE)

References