CVE-2026-58218

A flaw was found in Samba's internal DNS server where unauthenticated TKEY registration requests were added to the TKEY name cache before being rejected. A remote, unauthenticated attacker can exploit this behavior by sending a large number of TKEY requests with arbitrary names, exhausting the cache and evicting legitimate TKEY entries. This can prevent legitimate TSIG authentication for signed DNS queries, resulting in a denial of service.

• samba 2:4.24.5+dfsg-1 https://www.samba.org/samba/security/CVE-2026-58218-advisory.html