Skip to main content
VulnerabilityPublished

CVE-2026-50056: Zimbra Collaboration Suite · Argument Injection

Affects Zimbra Collaboration SuiteSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High.

Data as of 26 Oct 2026, 17:30 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 27% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-23.

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 23 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
ZimbraZimbra Collaboration SuiteAffected
  • <=10.1.21
Fixed in–

AI-suggested

Until a fix is available, restrict local access to the zimbra user and mailbox servers to trusted administrators only to reduce risk.

Description

CVE-2026-50056 is a local privilege escalation vulnerability in the zmmailboxdmgr launcher of Zimbra Collaboration Suite (ZCS). It allows the Unix zimbra account to execute arbitrary commands as root by exploiting a passwordless sudo interface that accepts unrestricted JVM arguments. The attack involves postponing Jetty's privilege drop and forcing heap exhaustion during startup to execute commands with root privileges. This requires local access as the zimbra user on a mailbox server and interrupts mailboxd during a malicious restart. Versions up to and including 10.1.21 are affected.

References

Community reviews

Loading reviews…