CVE-2026-58218

Samba: dns signing dos via tkey name cache exhaustion

MEDIUM
5.3
CVSS Score
Published: July 30, 2026 at 02:01 PM UTC
Updated: July 30, 2026 at 07:18 PM UTC
Products not identified yet

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.8%
SSVC
No known exploit

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.

Affected

We have no canonical product record for this CVE. The source names may not have matched any product.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (4)

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMredhat
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-410

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