Zimbra Collaboration Suite Local Privilege Escalation via zmmailboxdmgr JVM Argument Injection
Summary
| CVE | CVE-2026-50056 |
|---|---|
| State | PUBLISHED |
| Assigner | rapid7 |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-23 14:17:53 UTC |
| Updated | 2026-10-24 04:18:17 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 7.8 HIGH from [email protected]
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Problem Types: CWE-88 | CWE-88 CWE-88 Improper neutralization of argument delimiters in a command ('argument injection')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Zimbra | Zimbra Collaboration Suite | affected 10.1.21 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1 | [email protected] | www.rapid7.com | |
| wiki.zimbra.com/wiki/Zimbra_Security_Advisories | [email protected] | wiki.zimbra.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Jonah Burgess (CryptoCat), Senior Security Researcher, Rapid7 (en)
There are currently no legacy QID mappings associated with this CVE.