CVE-2026-89147
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.
Weakness
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.
References
- 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
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