CVE-2026-89147

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

Published Sep 11, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-8997-1 Net-SNMP vulnerability
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Net-SNMP through 5.9.5.2 Denial of Service via Blocking Unauthenticated SMUX Read
First Time appeared Net-snmp
Net-snmp net-snmp
Weaknesses CWE-1088
CWE-400
CPEs cpe:2.3:a:net-snmp:net-snmp:*:*:*:*:*:*:*:*
Vendors & Products Net-snmp
Net-snmp net-snmp
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Sep 24, 2026, 2:21 PM
Reserved
Sep 11, 2026, 1:23 AM
Status
Awaiting Analysis
Published
Sep 11, 2026, 11:16 AM
Modified
Sep 24, 2026, 8:44 PM