# CVE-2026-89147: net-snmp: Net-SNMP through 5.9.5.2 contains a denial of service vulnerability in the SMUX module where smux_accept() performs a...

CVE-2026-89147 is fixed in 11 products on 1 platform, first by libnetsnmptrapd40 5.9.1+dfsg-1ubuntu2.10, released September 11, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-89147
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0049
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 11, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libnetsnmptrapd40 Ubuntu 22.04.1 LTS (jammy) | 5.9.1+dfsg-1ubuntu2.10 | [libnetsnmptrapd40 5.9.1+dfsg-1ubuntu2.10](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libnetsnmptrapd40-5.9.1-dfsg-1ubuntu2.10.md) | Sep 11, 2026 |
| Linux | libnetsnmptrapd40t64 Ubuntu 24.04.5 LTS (noble) | 5.9.4+dfsg-1.1ubuntu3.3 | [libnetsnmptrapd40t64 5.9.4+dfsg-1.1ubuntu3.3](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libnetsnmptrapd40t64-5.9.4-dfsg-1.1ubuntu3.3.md) | Sep 11, 2026 |
| Linux | libnetsnmptrapd40t64 Ubuntu 26.04.1 LTS (resolute) | 5.9.4+dfsg-2ubuntu3.1 | [libnetsnmptrapd40t64 5.9.4+dfsg-2ubuntu3.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libnetsnmptrapd40t64-5.9.4-dfsg-2ubuntu3.1.md) | Sep 11, 2026 |
| Linux | libsnmp-base Ubuntu 22.04.1 LTS (jammy) | 5.9.1+dfsg-1ubuntu2.10 | [libsnmp-base 5.9.1+dfsg-1ubuntu2.10](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libsnmp-base-5.9.1-dfsg-1ubuntu2.10.md) | Sep 11, 2026 |
| Linux | libsnmp-base Ubuntu 24.04.5 LTS (noble) | 5.9.4+dfsg-1.1ubuntu3.3 | [libsnmp-base 5.9.4+dfsg-1.1ubuntu3.3](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libsnmp-base-5.9.4-dfsg-1.1ubuntu3.3.md) | Sep 11, 2026 |
| Linux | libsnmp-base Ubuntu 26.04.1 LTS (resolute) | 5.9.4+dfsg-2ubuntu3.1 | [libsnmp-base 5.9.4+dfsg-2ubuntu3.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libsnmp-base-5.9.4-dfsg-2ubuntu3.1.md) | Sep 11, 2026 |
| Linux | libsnmp-perl Ubuntu 22.04.1 LTS (jammy) | 5.9.1+dfsg-1ubuntu2.10 | [libsnmp-perl 5.9.1+dfsg-1ubuntu2.10](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libsnmp-perl-5.9.1-dfsg-1ubuntu2.10.md) | Sep 11, 2026 |
| Linux | libsnmp-perl Ubuntu 24.04.5 LTS (noble) | 5.9.4+dfsg-1.1ubuntu3.3 | [libsnmp-perl 5.9.4+dfsg-1.1ubuntu3.3](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libsnmp-perl-5.9.4-dfsg-1.1ubuntu3.3.md) | Sep 11, 2026 |
| Linux | libsnmp-perl Ubuntu 26.04.1 LTS (resolute) | 5.9.4+dfsg-2ubuntu3.1 | [libsnmp-perl 5.9.4+dfsg-2ubuntu3.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libsnmp-perl-5.9.4-dfsg-2ubuntu3.1.md) | Sep 11, 2026 |
| Linux | libsnmp40 Ubuntu 22.04.1 LTS (jammy) | 5.9.1+dfsg-1ubuntu2.10 | [libsnmp40 5.9.1+dfsg-1ubuntu2.10](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libsnmp40-5.9.1-dfsg-1ubuntu2.10.md) | Sep 11, 2026 |
| Linux | libsnmp40t64 Ubuntu 24.04.5 LTS (noble) | 5.9.4+dfsg-1.1ubuntu3.3 | [libsnmp40t64 5.9.4+dfsg-1.1ubuntu3.3](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libsnmp40t64-5.9.4-dfsg-1.1ubuntu3.3.md) | Sep 11, 2026 |
| Linux | libsnmp40t64 Ubuntu 26.04.1 LTS (resolute) | 5.9.4+dfsg-2ubuntu3.1 | [libsnmp40t64 5.9.4+dfsg-2ubuntu3.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libsnmp40t64-5.9.4-dfsg-2ubuntu3.1.md) | Sep 11, 2026 |
| Linux | net-snmp Debian 14 | 5.9.5.2+dfsg-3 | [DEBIAN-CVE-2026-89147](https://patchblox.com/security/data/fix/linux/debian-cve-2026-89147.md) | Sep 18, 2026 |
| Linux | snmp Ubuntu 22.04.1 LTS (jammy) | 5.9.1+dfsg-1ubuntu2.10 | [snmp 5.9.1+dfsg-1ubuntu2.10](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-snmp-5.9.1-dfsg-1ubuntu2.10.md) | Sep 11, 2026 |
| Linux | snmp Ubuntu 24.04.5 LTS (noble) | 5.9.4+dfsg-1.1ubuntu3.3 | [snmp 5.9.4+dfsg-1.1ubuntu3.3](https://patchblox.com/security/data/fix/linux/ubuntu-noble-snmp-5.9.4-dfsg-1.1ubuntu3.3.md) | Sep 11, 2026 |
| Linux | snmp Ubuntu 26.04.1 LTS (resolute) | 5.9.4+dfsg-2ubuntu3.1 | [snmp 5.9.4+dfsg-2ubuntu3.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-snmp-5.9.4-dfsg-2ubuntu3.1.md) | Sep 11, 2026 |
| Linux | snmpd Ubuntu 22.04.1 LTS (jammy) | 5.9.1+dfsg-1ubuntu2.10 | [snmpd 5.9.1+dfsg-1ubuntu2.10](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-snmpd-5.9.1-dfsg-1ubuntu2.10.md) | Sep 11, 2026 |
| Linux | snmpd Ubuntu 24.04.5 LTS (noble) | 5.9.4+dfsg-1.1ubuntu3.3 | [snmpd 5.9.4+dfsg-1.1ubuntu3.3](https://patchblox.com/security/data/fix/linux/ubuntu-noble-snmpd-5.9.4-dfsg-1.1ubuntu3.3.md) | Sep 11, 2026 |
| Linux | snmpd Ubuntu 26.04.1 LTS (resolute) | 5.9.4+dfsg-2ubuntu3.1 | [snmpd 5.9.4+dfsg-2ubuntu3.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-snmpd-5.9.4-dfsg-2ubuntu3.1.md) | Sep 11, 2026 |
| Linux | snmptrapd Ubuntu 22.04.1 LTS (jammy) | 5.9.1+dfsg-1ubuntu2.10 | [snmptrapd 5.9.1+dfsg-1ubuntu2.10](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-snmptrapd-5.9.1-dfsg-1ubuntu2.10.md) | Sep 11, 2026 |
| Linux | snmptrapd Ubuntu 24.04.5 LTS (noble) | 5.9.4+dfsg-1.1ubuntu3.3 | [snmptrapd 5.9.4+dfsg-1.1ubuntu3.3](https://patchblox.com/security/data/fix/linux/ubuntu-noble-snmptrapd-5.9.4-dfsg-1.1ubuntu3.3.md) | Sep 11, 2026 |
| Linux | snmptrapd Ubuntu 26.04.1 LTS (resolute) | 5.9.4+dfsg-2ubuntu3.1 | [snmptrapd 5.9.4+dfsg-2ubuntu3.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-snmptrapd-5.9.4-dfsg-2ubuntu3.1.md) | Sep 11, 2026 |
| Linux | tkmib Ubuntu 22.04.1 LTS (jammy) | 5.9.1+dfsg-1ubuntu2.10 | [tkmib 5.9.1+dfsg-1ubuntu2.10](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-tkmib-5.9.1-dfsg-1ubuntu2.10.md) | Sep 11, 2026 |
| Linux | tkmib Ubuntu 24.04.5 LTS (noble) | 5.9.4+dfsg-1.1ubuntu3.3 | [tkmib 5.9.4+dfsg-1.1ubuntu3.3](https://patchblox.com/security/data/fix/linux/ubuntu-noble-tkmib-5.9.4-dfsg-1.1ubuntu3.3.md) | Sep 11, 2026 |
| Linux | tkmib Ubuntu 26.04.1 LTS (resolute) | 5.9.4+dfsg-2ubuntu3.1 | [tkmib 5.9.4+dfsg-2ubuntu3.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-tkmib-5.9.4-dfsg-2ubuntu3.1.md) | Sep 11, 2026 |

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Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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