Common Weakness Enumeration
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CWE-606
Unchecked Input for Loop Condition
The product does not properly check inputs that are used for loop conditions, potentially leading to a denial of service or other consequences because of excessive looping.
CVE-2026-5950 (GCVE-0-2026-5950)
Vulnerability from cvelistv5 – Published: 2026-05-20 13:10 – Updated: 2026-05-20 13:38
VLAI
Title
Unbounded resend loop in BIND 9 resolver
Summary
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.
Severity
5.3 (Medium)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-606 - Unchecked Input for Loop Condition
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://kb.isc.org/docs/cve-2026-5950 | vendor-advisory |
| https://downloads.isc.org/isc/bind9/9.18.49 | patch |
| https://downloads.isc.org/isc/bind9/9.20.23 | patch |
| https://downloads.isc.org/isc/bind9/9.21.22 | patch |
Impacted products
Date Public
2026-05-20 00:00
Credits
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Mitigation
Phase: Implementation
Description:
- Do not use user-controlled data for loop conditions.
Mitigation
Phase: Implementation
Description:
- Perform input validation.
No CAPEC attack patterns related to this CWE.