Resource exhaustion in Samba - CVE-2026-58218
Published: July 28, 2026 / Updated: July 29, 2026
Vulnerability identifier: #VU139943
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-58218
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Affected software:
Samba
Samba
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper resource management in the DNS TKEY name cache when repeatedly registering TKEY names. A remote attacker can repeatedly register names to cause a denial of service.
The issue can flood the cache and expunge legitimate TKEYs, practically blocking DNS TSIG signing.
How to mitigate CVE-2026-58218
Install security update from vendor's website.