Net-SNMP through 5.9.5.2 Denial of Service via Blocking Unauthenticated SMUX Read (CVE-2026-89147) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89147

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

Answer in brief

CVE-2026-89147 records a Unknown severity vulnerability in Net-SNMP through 5.9.5.2 Denial of Service via Blocking Unauthenticated SMUX Read. The current sources do not mark it as known exploited. The current feed maps net-snmp/Net-SNMP (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 11, 2026Updated Sep 11, 2026Source checked Sep 11, 2026First seen by HOL Sep 11, 2026Material review Sep 11, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps net-snmp/Net-SNMP (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
net-snmp/Net-SNMPgeneric	0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for net-snmp/Net-SNMP.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 11, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.