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

mediumCVSS 5.3CVE-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.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: medium — CVSS 5.3
Published: 2026-07-30
Last updated: 2026-07-30
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-58218

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Moderate exploitation riskCVE-2026-582181.1% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 62% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-58218	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

high[NEW] [high] Samba: Multiple vulnerabilitiescert-bund
unknownUSN-8621-1: Samba vulnerabilitiesubuntu
unknownMultiple vulnerabilities in Samba (July 28, 2026)cert-fr-avis
unknownDSA-6401-1 samba - security updatedebian

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

Details

Exploitation outlook

Referenced CVEs

Same CVEs, other sources

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