CVE-2026-89147
Net-SNMP through 5.9.5.2 Denial of Service via Blocking Unauthenticated SMUX Read
- State
- Published
- Severity
- 8.7 High
- Published
- Sep 11, 2026
- Updated
- Sep 24, 2026
- Reserved
- 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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.7 High | 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 | VulnCheck |
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | VulnCheck |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
Net-SNMPnet-snmp |
|
References
- Unauthenticated remote denial of service in Net-SNMP snmpd via blocking pre-authentication SMUX readthird-party-advisory
- agent/mibgroup/smux/smux.c at v5.9.5.2technical-description
- Productproduct
- VulnCheck Advisory: Net-SNMP through 5.9.5.2 Denial of Service via Blocking Unauthenticated SMUX Readthird-party-advisory
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