CVE-2026-73576 Weak cryptography in Collaboration
Weak JWT secret generation in Zimbra's OnlyOffice integration allows attackers to brute-force the secret and forge tokens, potentially leading to unauthorized access.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-73576?
CVE-2026-73576 is a medium-severity vulnerability in Synacor Zimbra Collaboration Suite, published on 13 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-1241
Which versions are affected by CVE-2026-73576?
It affects 1 product.
Products include Synacor Zimbra Collaboration Suite.
How do I fix CVE-2026-73576?
No fix has been published for CVE-2026-73576 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-73576 being exploited?
There is no known exploitation of CVE-2026-73576 in the wild and no public exploit code.
Other vulnerabilities in Synacor Zimbra Collaboration Suite
- CVE-2024-45519 Synacor Zimbra Collaboration Suite (ZCS) Command Execution
- CVE-2022-41352 Synacor Zimbra Collaboration Suite (ZCS) Arbitrary File Upload
- CVE-2022-37042 Synacor Zimbra Collaboration Suite (ZCS) Authentication Bypass
- CVE-2022-27924 Synacor Zimbra Collaboration Suite (ZCS) Command Injection
- CVE-2020-7796 Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery
Sources
Also known as GHSA-j7xr-pwqg-qw2q.