CVE-2026-89147

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-11. a secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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
EG Score
7.5(high)
EG Risk
65(Attend)
EG Risk 65/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
20%
KEV
Not listed

Published

September 11, 2026

Last Modified

September 15, 2026

Advisory Details (4)

Auto-updated Sep 11, 2026
No patch confirmed yet.
generic

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

https://www.vulncheck.com/advisories/net-snmp-through-5.9.5.2-denial-of-service-via-blocking-unauthenticated-smux-read
generic

GitHub - net-snmp/net-snmp: A SNMP application library, tools and daemon · GitHub

https://github.com/net-snmp/net-snmp
generic

net-snmp/agent/mibgroup/smux/smux.c at v5.9.5.2 · net-snmp/net-snmp · GitHub

https://github.com/net-snmp/net-snmp/blob/v5.9.5.2/agent/mibgroup/smux/smux.c
generic

Unauthenticated remote denial of service in `snmpd` via blocking pre-authentication SMUX read · GitHub

https://gist.github.com/thesmartshadow/001cea595e75fed6aaea7389666dc9eb

Vendor Advisories for CVE-2026-89147(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 30× in last 7d / 35× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 23:16 UTCEG score recompute
  2. 2026-09-18 23:16 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 10:19 UTCGHSA enrichment
  5. 2026-09-17 21:22 UTCEG score recompute
  6. 2026-09-17 21:22 UTCGHSA enrichment
  7. 2026-09-17 19:32 UTCEPSS rescore
  8. 2026-09-17 08:25 UTCGHSA enrichment
  9. 2026-09-16 19:28 UTCEG score recompute
  10. 2026-09-16 19:28 UTCGHSA enrichment
  11. 2026-09-16 14:09 UTCEPSS rescore
  12. 2026-09-16 06:30 UTCEG score recompute
  13. 2026-09-16 06:30 UTCGHSA enrichment
  14. 2026-09-16 05:15 UTCEPSS rescore
  15. 2026-09-15 17:33 UTCEG score recompute
  16. 2026-09-15 17:33 UTCGHSA enrichment
  17. 2026-09-15 16:18 UTCEG score recompute
  18. 2026-09-15 16:18 UTCGHSA enrichment
  19. 2026-09-15 06:08 UTCEG score recompute
  20. 2026-09-15 06:08 UTCGHSA enrichment
  21. 2026-09-15 03:12 UTCEPSS rescore
  22. 2026-09-14 17:11 UTCGHSA enrichment
  23. 2026-09-14 04:13 UTCEG score recompute
  24. 2026-09-14 04:13 UTCGHSA enrichment
  25. 2026-09-13 16:48 UTCEPSS rescore
Show 10 more
  1. 2026-09-13 15:16 UTCGHSA enrichment
  2. 2026-09-13 02:17 UTCEG score recompute
  3. 2026-09-13 02:17 UTCGHSA enrichment
  4. 2026-09-12 15:02 UTCEPSS rescore
  5. 2026-09-12 13:20 UTCGHSA enrichment
  6. 2026-09-12 00:23 UTCEG score recompute
  7. 2026-09-12 00:23 UTCGHSA enrichment
  8. 2026-09-11 11:26 UTCEG score recompute
  9. 2026-09-11 10:55 UTCEG score recompute
  10. 2026-09-11 10:54 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-89147?
CVE-2026-89147 is a high vulnerability published on September 11, 2026. 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…
When was CVE-2026-89147 disclosed?
CVE-2026-89147 was first published in the National Vulnerability Database on September 11, 2026, with the most recent update on September 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-89147 actively exploited?
CVE-2026-89147 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 79.7% of all scored CVEs.
What is the CVSS score of CVE-2026-89147?
CVE-2026-89147 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-89147?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-89147, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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