9Router is an AI router & token saver. From 0.4.30 until 0.4.37, 9Router's src/proxy.js middleware did not protect /api/cli-tools/* and /api/mcp/*, allowing unauthenticated registration of customPlugins through src/app/api/cli-tools/cowork-settings/route.js and command execution through the MCP bridge. This vulnerability is fixed in 0.4.37.
CVE-2026-46339
“—” beside the score: it is equal to the CVSS score beside it.
This critical-severity CVE scores 10.0 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 3.4% (88th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
- CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
A fix is available — apply it.
- CVSS v3
- 10.0
- EG Score
- 10.0CRITICALmedium confidence
- EG Risk
- 76EG Risk 76/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity100% × 45%Impact severity (EG Severity): CVSS 10.0 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation40% × 40%EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.Automatability100% × 15%CISA's SSVC Automatable value: yes (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- 3.4%
- EPSS %ILE
- 88th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (10.0): severity, escalated by confirmed exploitation. This CVE's 10.0 is its impact severity (EG Severity), not escalated.
- EG Severity
- 10.0 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
- EG Likelihood
- 3.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-19). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track* at medium mission impactTrack at low, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)3 days if the affected system is publicly exposed; 60 days if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
May 19, 2026
Last Modified
July 16, 2026
Advisory Details (2)
Auto-updated Oct 16, 2026Unauthenticated Remote Code Execution via unprotected MCP custom plugin routes · Advisory · decolua/9router · GitHub
https://github.com/decolua/9router/security/advisories/GHSA-fhh6-4qxv-rpqjcommit 992f4db4a0d8 (decolua/9router)
Patch available: decolua/9router v0.4.38 (contains commit 992f4db4a0d8)
https://github.com/decolua/9router/commit/992f4db4a0d858bcc86b4786f2abab117a6ccdf8Vendor Advisories for CVE-2026-46339(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
npm(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| 9router | — |
| — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 14× in last 7d / 35× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 99 of 113 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 14 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-19 23:27 UTCEG score recompute
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-18 22:06 UTCEG score recompute
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-18 03:37 UTCEG score recompute
- 2026-10-17 20:34 UTCEG score recompute
- 2026-10-17 16:34 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-16 19:12 UTCEG score recompute
- 2026-10-16 16:42 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-15 16:32 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-15 16:21 UTCEG score recompute
- 2026-10-14 16:33 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-14 10:33 UTCEG score recompute
- 2026-10-13 16:34 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-13 09:02 UTCEG score recompute
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-12 16:03 UTCEG score recompute
- 2026-10-11 19:45 UTCEG score recompute
- 2026-10-11 17:00 UTCEG score recompute
- 2026-10-11 14:25 UTCEG score recompute
- 2026-10-11 13:48 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-08 17:12 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 3.4% · 88th percentile
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- 2026-10-06 15:18 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-03 14:25 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-10-01 19:50 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-09-30 13:32 UTCOSV refresh
- 2026-09-28 13:51 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-09-27 13:48 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-09-26 15:59 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-09-23 17:53 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-09-17 19:31 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-09-16 14:08 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-09-16 05:15 UTCEPSS rescoreEPSS 3.4% · 88th percentile
- 2026-09-12 15:01 UTCEPSS rescoreEPSS 3.4% · 87th percentile
- 2026-09-11 20:23 UTCOSV refresh
- 2026-09-11 14:53 UTCEPSS rescoreEPSS 3.4% · 87th percentile
- 2026-09-11 09:37 UTCEPSS rescoreEPSS 3.4% · 87th percentile
- 2026-09-10 09:34 UTCEPSS rescoreEPSS 3.4% · 87th percentile
- 2026-09-08 22:00 UTCEPSS rescoreEPSS 3.4% · 87th percentile
- 2026-09-07 16:01 UTCEPSS rescoreEPSS 3.4% · 87th percentile
- 2026-09-06 13:47 UTCEPSS rescoreEPSS 3.4% · 87th percentile
- 2026-09-04 05:06 UTCEPSS rescoreEPSS 3.4% · 87th percentile
- 2026-09-02 14:12 UTCEPSS rescoreEPSS 3.4% · 87th percentile
- 2026-09-01 13:54 UTCEPSS rescoreEPSS 3.4% · 87th percentile
- 2026-08-30 19:17 UTCEPSS rescoreEPSS 3.4% · 87th percentile
- 2026-08-30 01:22 UTCEPSS rescoreEPSS 3.4% · 87th percentile
- 2026-08-28 21:41 UTCEPSS rescoreEPSS 3.4% · 87th percentile
- 2026-08-27 14:25 UTCEPSS rescoreEPSS 3.4% · 87th percentile
- 2026-08-26 14:46 UTCEPSS rescoreEPSS 3.4% · 87th percentile
- 2026-08-25 13:49 UTCEPSS rescoreEPSS 3.4% · 87th percentile
- 2026-08-23 17:00 UTCEG score recompute
- 2026-08-23 00:19 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-21 23:49 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-21 23:36 UTCEG score recompute
- 2026-08-20 22:55 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-20 19:00 UTCEG score recompute
- 2026-08-19 17:04 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-18 13:48 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-17 13:47 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-16 16:56 UTCEG score recompute
- 2026-08-16 14:56 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-16 03:33 UTCEG score recompute
- 2026-08-16 02:14 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-15 01:30 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-14 02:06 UTCEG score recompute
- 2026-08-13 22:00 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-12 15:47 UTCEG score recompute
- 2026-08-12 13:51 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-11 13:53 UTCEG score recompute
- 2026-08-11 00:38 UTCEG score recompute
- 2026-08-11 00:00 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-09 01:35 UTCEG score recompute
- 2026-08-08 16:37 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-07 19:33 UTCEG score recompute
- 2026-08-06 16:45 UTCEG score recompute
- 2026-08-06 13:47 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-05 21:20 UTCEG score recompute
- 2026-08-05 19:17 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-04 15:10 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-04 10:39 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-03 16:57 UTCEG score recompute
- 2026-08-03 10:36 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-02 05:16 UTCEG score recompute
- 2026-08-02 02:27 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-08-01 17:52 UTCEG score recompute
- 2026-08-01 04:16 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-07-30 16:28 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-07-30 01:30 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-07-28 15:36 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-07-27 14:13 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-07-26 14:54 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-07-25 14:18 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
- 2026-07-24 14:17 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
Public detection templates
(1 reference)A public Nuclei detection template is referenced for this CVE. A detection template checks whether a system is affected; it is not necessarily exploit code.
- Nucleihttp/cves/2026/CVE-2026-46339.yamlPublished Jul 15, 2026
9Router <= 0.4.36 - Unauthenticated RCE
Open source ↗
Related CVEs(same product + same CWE)
Same product
10 shownnpm:9router
Frequently asked(5)
What is CVE-2026-46339?
When was the CVE record for CVE-2026-46339 published?
Is CVE-2026-46339 actively exploited?
What is the CVSS score of CVE-2026-46339?
How do I remediate CVE-2026-46339?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-46339
Is Your Infrastructure Affected by CVE-2026-46339?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.