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TI-2026-79918 Aliases CVE-2026-93640GHSA-m5xr-vr49-p6gj

Zimbra Collaboration Suite lets local users escalate privileges

Priority LOW 35CWE-732Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

The optional dnscache package of Zimbra Collaboration Suite (ZCS) from 0 through 10.1.21 is affected. The passwordless sudo policy lets the Unix zimbra account pass arbitrary arguments to zmunbound, which forwards them to Unbound without restricting the configuration path (CWE-732). A local user with low privileges can read root-readable files such as password hashes and private keys, create or append to root-owned files, and corrupt privileged configuration so that affected services fail to start.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

A local privilege escalation vulnerability in the optional dnscache package of Zimbra Collaboration Suite (ZCS) allows the Unix zimbra account to access files with root privileges. The passwordless sudo policy permits arbitrary arguments to zmunbound, whose wrapper forwards them to Unbound without restricting the configuration path. An attacker can supply a configuration that retains root privileges and disables the chroot. Include directives expose root-readable file contents through parser errors, while an attacker-selected logfile path creates a root-owned file or appends Unbound log records to an existing file. This can disclose password hashes and private keys and corrupt privileged configuration files, preventing affected services from starting with the modified configuration. The affected configuration is present in ZCS 10.1.16 and 10.1.21 dnscache packages.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00124 2nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ZimbraZimbra Collaboration Suiteup to 10.1.21—No fix listedCNA
  • Zimbra Collaboration Suite VendorZimbra Affected up to 10.1.21 Fixed in — No fix listed CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:*——Synacor
  • cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:* Versions — — ·Synacor

Remediation

The sources list no fixed version for Zimbra Collaboration Suite.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Timeline

  1. 2026-10-23 Threatist record created from CVE-2026-93640
  2. 2026-10-23 Alias added: GHSA-m5xr-vr49-p6gj
  3. 2026-10-24 CISA SSVC decision points changed

References

Advisory 1

Other 1

  • TI-2026-51660 OS command injection in Zimbra Collaboration KEVCVSS 3.1HIGH 8.9
  • TI-2025-40820 Cross-site scripting in Zimbra Collaboration KEVCVSS 3.1HIGH 7.2
  • TI-2024-18266 An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0. KEVCVSS 3.1MEDIUM 6.1
  • TI-2024-30553 An issue was discovered in Zimbra Collaboration (ZCS) 10.1.x before 10.1.1, 10.0.x before… CVSS 3.1HIGH 8.8
  • TI-2022-13998 Zimbra Collaboration Open Source 8.8.15 does not encrypt the initial-login randomly… CVSS 3.1CRITICAL 9.8
  • TI-2026-63080 Path traversal in Zimbra Collaboration Suite CVSS 3.1CRITICAL 9.8
See all 94 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences