CVE-2026-58218
Medium
Description
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.
SeverityMedium
CVSS5.3
Exploit probability—
Productinternal DNS server
PublishedJul 30, 2026
First seenJul 30, 2026
Weakness typeCWE-410CWE-410
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Samba internal DNS server | No range specified | — |
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