Vulnerability Report

CVE-2026-5950

Title: BIND 9 Unbounded Resend Loop DoS

DoS

Proof Of Concept

No public PoC currently indexed for CVE-2026-5950.

CWE Category CWE-606
Published Date May 20, 2026
Modified Date May 21, 2026
Exploit Status Not Found
Score 5.3 CVSS v3.1
Exploit Probability (EPSS)
0.14%

Vulnerability Summary

CVE-2026-5950: An unbounded resend loop vulnerability exists in the BIND 9 resolver state machine during bad-server handling, enabling a remote unauthenticated attacker to cause severe resource exhaustion by sending queries that trigger specific retry conditions. This issue affects BIND 9 versions 9.18.36 through 9.18.48, 9.20.8 through 9.20.22, 9.21.7 through 9.21.21, 9.18.36-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.

Impacted Vendors

I
isc 1

Reference Links

https://downloads.isc.org/isc/bind9/9.18.49 https://downloads.isc.org/isc/bind9/9.20.23 https://downloads.isc.org/isc/bind9/9.21.22 https://kb.isc.org/docs/cve-2026-5950
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
5.3
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-5950 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected Stack

No specific products linked.