CVE-2026-89147
Net-SNMP through 5.9.5.2 Denial of Service via Blocking Unauthenticated SMUX Read
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-1088 CWE-400 |
| Vendor | net-snmp |
| Product | net-snmp |
| Published | Sep 11, 2026 |
| Last Updated | Sep 15, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
net-snmp / Net-SNMP
0 ≤ 5.9.5.2
References
gist.github.com: https://gist.github.com/thesmartshadow/001cea595e75fed6aaea7389666dc9eb github.com: https://github.com/net-snmp/net-snmp/blob/v5.9.5.2/agent/mibgroup/smux/smux.c github.com: https://github.com/net-snmp/net-snmp vulncheck.com: https://www.vulncheck.com/advisories/net-snmp-through-5.9.5.2-denial-of-service-via-blocking-unauthenticated-smux-read
Credits
🔍 Ali Firas