CVE-2026-58218
Samba: dns signing dos via tkey name cache exhaustion
MEDIUM 5.3
At a glance
- Source
- NVD
- EPSS
- EPSS 0.78 % · percentile 56 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- redhat
- NVD status
- Awaiting Analysis
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.
Weaknesses (CWE)
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L | redhat |
| CVSS 3.1 | MEDIUM 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L | NVD · secalert@redhat.com (Secondary) |
European references
- ENISA EUVD · EUVD-2026-51128
- GCVE · GCVE-0-2026-58218
CERT-FR advisories
- CERTFR-2026-AVI-0939 — Multiples vulnérabilités dans Samba · cert.ssi.gouv.fr
Affected products
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |