CVE-2026-89147
Severity CVSS v4.0:
HIGH
Type:
CWE-400
Uncontrolled Resource Consumption ('Resource Exhaustion')
Publication date:
11/09/2026
Last modified:
24/09/2026
Description
Net-SNMP through 5.9.5.2 contains a denial of service vulnerability in the SMUX module where smux_accept() performs an unauthenticated blocking read without timeout on newly accepted connections. An unauthenticated remote client can connect to the SMUX listener and send no data, causing the single-threaded snmpd main loop to block indefinitely and suspend all SNMP processing.
Impact
Base Score 4.0
8.70
Severity 4.0
HIGH
Base Score 3.x
7.50
Severity 3.x
HIGH
References to Advisories, Solutions, and Tools
- https://gist.github.com/thesmartshadow/001cea595e75fed6aaea7389666dc9eb
- https://github.com/net-snmp/net-snmp
- https://github.com/net-snmp/net-snmp/blob/v5.9.5.2/agent/mibgroup/smux/smux.c
- https://www.vulncheck.com/advisories/net-snmp-through-5.9.5.2-denial-of-service-via-blocking-unauthenticated-smux-read
- https://gist.github.com/thesmartshadow/001cea595e75fed6aaea7389666dc9eb


