CVE-2026-50056 Zimbra Collaboration Suite Local Privilege Escalation via zmmailboxdmgr JVM Argument Injection
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-50056?
CVE-2026-50056 is a high-severity vulnerability in Zimbra Collaboration Suite, published on 23 Oct 2026.
Official description
A local privilege escalation vulnerability in the zmmailboxdmgr launcher of Zimbra Collaboration Suite (ZCS) allows the Unix zimbra account to execute arbitrary commands as root. The passwordless sudo interface accepts JVM arguments that are not adequately restricted. An attacker can postpone Jetty's privilege drop, register an OnOutOfMemoryError command and force heap exhaustion during startup, causing the command to execute while the JVM still runs as root. Exploitation requires local command execution as zimbra on a mailbox server and interrupts mailboxd during the malicious restart. ZCS 10.1.16 and 10.1.21 are affected.
Weakness: CWE-88
Which versions are affected by CVE-2026-50056?
How do I fix CVE-2026-50056?
No fix has been published for CVE-2026-50056 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-50056 being exploited?
There is no known exploitation of CVE-2026-50056 in the wild and no public exploit code.
Sources
Also known as GHSA-ww99-8662-82q8.