CVE-2026-50056: Zimbra Collaboration Suite Local Privilege Escalation via zmmailboxdmgr JVM Argument Injection
Zimbra · Zimbra Collaboration Suite
Vendor fix available · Affected: Zimbra Collaboration Suite · Exploitation: not established
ExploitationNot established
Not in CISA KEV as of catalogue 2026.11.13 (13 Nov)
- In CISA KEV: not seen
- Exploited (reported): not seen
- Scanning observed: not seen
- Proof of concept public: not seen
- Not establishedNothing in the sources we check
Higher than 28% of scored CVEs
Not scored yet. NVD has not published a CVSS score.
DescriptionNVD
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.
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Vendor
- Zimbra
- Published
- October 2026
Coverage1 article · 1 outlet
First in our coverage: SecurityOnline, 27 Oct.
- Rapid7 Discloses 17 Flaws in Zimbra Collaboration SuiteSecurityOnline · first in our coverage · mentions it in passing
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