CVE-2026-5950

medium

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.

References

https://kb.isc.org/docs/cve-2026-5950

https://downloads.isc.org/isc/bind9/9.21.22

https://downloads.isc.org/isc/bind9/9.20.23

https://downloads.isc.org/isc/bind9/9.18.49

Details

Source: Mitre, NVD

Published: 2026-05-20

Updated: 2026-05-20

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

Severity: Medium

CVSS v3

Base Score: 5.3

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Severity: Medium