CVE-2026-73576: Weak Encryption
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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Zimbra Collaboration (ZCS)to a version that resolves this vulnerability.Fixed in 10.1.17 - Operational
After applying the fix in Zimbra Collaboration (ZCS) before 10.1.17, regenerate/rotate the OnlyOffice integration JWT signing secret value `zimbraDocumentEditingJwtSecret` because it is generated with insufficient entropy.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-73576?
The severity of CVE-2026-73576 is classified as medium with a score of 6.3.
How do I fix CVE-2026-73576?
To fix CVE-2026-73576, upgrade your Zimbra Collaboration Server to version 10.1.17 or later.
What is the impact of CVE-2026-73576?
CVE-2026-73576 allows attackers to exploit weak cryptographic key generation in OnlyOffice integration, potentially leading to unauthorized access.
Is CVE-2026-73576 related to weak encryption?
Yes, CVE-2026-73576 is categorized under weak encryption due to insecure random number generation.
When was CVE-2026-73576 published?
CVE-2026-73576 was published on August 13, 2026.