Medium 5.3Published Jul 30, 2026

CVE-2026-58218Samba: dns signing dos via tkey name cache exhaustion

Updated under an hour ago (Oct 27, 2026, 11:00 PM ET)

Does this affect you?

It affects Red Hat Enterprise Linux 10 and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for Red Hat Enterprise Linux 10

Exploited in the last 30 days

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.

CVSS: 5.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness (CWE): CWE-410
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: redhat
NVD analysis: Awaiting Analysis
Record last updated: Jul 30, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Red Hat Red Hat Enterprise Linux 10 redhat:enterprise_linux	10	CNA record
Red Hat Red Hat OpenShift Container Platform 4 redhat:openshift	4	CNA record

References

References

https://access.redhat.com/security/cve/CVE-2026-58218	vdb-entry, x-refsource-redhat
https://bugzilla.redhat.com/show_bug.cgi?id=2502728	issue-tracking, x-refsource-redhat
https://bugzilla.samba.org/show_bug.cgi?id=16115
https://www.samba.org/samba/security/CVE-2026-58218.html

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.