Vulnerability Description
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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Isc | Bind | >= 9.18.36, < 9.18.49 |
Related Weaknesses (CWE)
References
- https://downloads.isc.org/isc/bind9/9.18.49Patch
- https://downloads.isc.org/isc/bind9/9.20.23Patch
- https://downloads.isc.org/isc/bind9/9.21.22Patch
- https://kb.isc.org/docs/cve-2026-5950Vendor Advisory
FAQ
What is CVE-2026-5950?
CVE-2026-5950 is a vulnerability with a CVSS score of 5.3 (MEDIUM). 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...
How severe is CVE-2026-5950?
CVE-2026-5950 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-5950?
Check the references section above for vendor advisories and patch information. Affected products include: Isc Bind.