CVE-2026-5950
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk43th percentile - higher than 43% of all known CVEs
Summary
An unbounded resend loop in the BIND 9 resolver state machine during bad-server handling. A remote unauthenticated attacker can cause severe resource exhaustion by sending queries that trigger specific retry conditions.
Risk Assessment
Potential complete resource exhaustion of the DNS server, leading to denial of service (DoS).
Recommendation
Update BIND 9 to a version outside the vulnerable ranges (9.18.36-9.18.48, 9.20.8-9.20.22, 9.21.7-9.21.21, and S1 versions).
Original NVD description (English source)
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.