Samba: dns signing dos via tkey name cache exhaustion
Priority LOW 31CWE-410Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00784 56th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | No fix listed | CNA |
- Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift Container Platform 4 VendorRed Hat Affected — Fixed in — No fix listed CNA
CPE names CNA · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:/o:redhat:enterprise_linux:10 | 10 | — | Red Hat |
| cpe:/o:redhat:enterprise_linux:6 | 6 | — | Red Hat |
| cpe:/o:redhat:enterprise_linux:7 | 7 | — | Red Hat |
| cpe:/o:redhat:enterprise_linux:8 | 8 | — | Red Hat |
| cpe:/o:redhat:enterprise_linux:9 | 9 | — | Red Hat |
| cpe:/a:redhat:openshift:4 | 4 | — | Red Hat |
- cpe:/o:redhat:enterprise_linux:10 Versions 10 — ·Red Hat
- cpe:/o:redhat:enterprise_linux:6 Versions 6 — ·Red Hat
- cpe:/o:redhat:enterprise_linux:7 Versions 7 — ·Red Hat
- cpe:/o:redhat:enterprise_linux:8 Versions 8 — ·Red Hat
- cpe:/o:redhat:enterprise_linux:9 Versions 9 — ·Red Hat
- cpe:/a:redhat:openshift:4 Versions 4 — ·Red Hat
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 7 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-02 Threatist record created from CVE-2026-58218
- 2026-10-03 Alias added: GHSA-qcxx-8h4x-9v7w
- 2026-11-06 Affected versions changed · Red Hat
References
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- TI-2018-16080 A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153… KEVCVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-58218 · CVE Program
- CVE-2026-58218 · NVD
- FIRST EPSS
- GHSA-qcxx-8h4x-9v7w · GitHub Advisory Database · CC BY 4.0
- CVE-2026-58218 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences