CVE-2026-89147

Net-SNMP through 5.9.5.2 Denial of Service via Blocking Unauthenticated SMUX Read

Published: Sep 11, 2026Updated: Sep 15, 2026 Sources: CVE List NVDCWE-400

7.5HIGH

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.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:LAttack Complexity

Low

PR:NPrivileges Required

None

UI:NUser Interaction

None

Scope

S:UScope

Unchanged

Impact

C:NConfidentiality

None

I:NIntegrity

None

A:HAvailability

High

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Weaknesses

CWE-400 CWE-1088

Affected Products

net-snmp

oss-projectaka net-snmp suite

Net-SNMPLibrary

OSS Libraries / generic-library

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique

Impact

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References

https://gist.github.com/thesmartshadow/001cea595e75fed6aaea7389666dc9eb

gist.github.com

https://github.com/net-snmp/net-snmp

github.com

https://github.com/net-snmp/net-snmp/blob/v5.9.5.2/agent/mibgroup/smux/smux.c

github.com

and 1 more references View all →

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