CVE Catalog

CVE-2026-93640

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.14%

3th percentile - higher than 3% of all known CVEs

Summary

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. This can disclose password hashes and private keys and corrupt privileged configuration files.

Risk Assessment

A local attacker with the zimbra account can read password hashes and private keys and corrupt service configuration, leading to data disclosure and denial of service.

Recommendation

Update the ZCS dnscache package to the patched version. Restrict the sudo policy for zmunbound and secure the Unbound configuration directory.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS