CVE-2026-93640 Zimbra Collaboration Suite Local Privilege Escalation via Unrestricted zmunbound Sudo Configuration
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-93640?
CVE-2026-93640 is a high-severity vulnerability in Zimbra Collaboration Suite, published on 23 Oct 2026.
Official description
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.
Weakness: CWE-732
Which versions are affected by CVE-2026-93640?
How do I fix CVE-2026-93640?
No fix has been published for CVE-2026-93640 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-93640 being exploited?
There is no known exploitation of CVE-2026-93640 in the wild and no public exploit code.
Sources
Also known as GHSA-m5xr-vr49-p6gj.