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.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
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

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-11 11:16

Updated : 2026-09-15 17:17

NVD link : CVE-2026-89147

Mitre link : CVE-2026-89147

CVE.ORG link : CVE-2026-89147

JSON object : View

Products Affected

No product.

CWE

CWE-400

Uncontrolled Resource Consumption

CWE-1088

Synchronous Access of Remote Resource without Timeout

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