CVE-2026-46339

CRITICALPre-NVD 10.010.0
EchelonGraph scoreMEDIUM confidence

“—” 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.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Elevated
10.0EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 3.4%CVSS: 10.0Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

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.

CVSS v3
10.0
EG Score
10.0CRITICALmedium confidence
EG Risk
76
EG 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, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
GitHub advisoryMentions a patch (unverified)🟡 PoC Available

Unauthenticated Remote Code Execution via unprotected MCP custom plugin routes · Advisory · decolua/9router · GitHub

https://github.com/decolua/9router/security/advisories/GHSA-fhh6-4qxv-rpqj
GitHub commit Patch Available

commit 992f4db4a0d8 (decolua/9router)

Patch available: decolua/9router v0.4.38 (contains commit 992f4db4a0d8)

https://github.com/decolua/9router/commit/992f4db4a0d858bcc86b4786f2abab117a6ccdf8

Vendor 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)
PackageVulnerable rangeFix by version rangeDependents
9router—
  • 0.4.30 up to 0.4.37: fixed in 0.4.37
—

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.

  1. 2026-10-19 23:27 UTCEG score recompute
  2. 2026-10-19 16:32 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  3. 2026-10-18 22:06 UTCEG score recompute
  4. 2026-10-18 16:32 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  5. 2026-10-18 03:37 UTCEG score recompute
  6. 2026-10-17 20:34 UTCEG score recompute
  7. 2026-10-17 16:34 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  8. 2026-10-16 19:12 UTCEG score recompute
  9. 2026-10-16 16:42 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  10. 2026-10-15 16:32 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  11. 2026-10-15 16:21 UTCEG score recompute
  12. 2026-10-14 16:33 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  13. 2026-10-14 10:33 UTCEG score recompute
  14. 2026-10-13 16:34 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  15. 2026-10-13 09:02 UTCEG score recompute
  16. 2026-10-12 16:34 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  17. 2026-10-12 16:03 UTCEG score recompute
  18. 2026-10-11 19:45 UTCEG score recompute
  19. 2026-10-11 17:00 UTCEG score recompute
  20. 2026-10-11 14:25 UTCEG score recompute
  21. 2026-10-11 13:48 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  22. 2026-10-10 20:00 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  23. 2026-10-09 20:07 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  24. 2026-10-08 17:12 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  25. 2026-10-07 23:48 UTCEPSS rescoreEPSS 3.4% · 88th percentile
Show 74 more
  1. 2026-10-06 15:18 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  2. 2026-10-05 17:43 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  3. 2026-10-03 14:25 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  4. 2026-10-01 19:50 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  5. 2026-09-30 15:03 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  6. 2026-09-30 13:32 UTCOSV refresh
  7. 2026-09-28 13:51 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  8. 2026-09-27 13:48 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  9. 2026-09-26 15:59 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  10. 2026-09-23 17:53 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  11. 2026-09-18 19:28 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  12. 2026-09-17 19:31 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  13. 2026-09-16 14:08 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  14. 2026-09-16 05:15 UTCEPSS rescoreEPSS 3.4% · 88th percentile
  15. 2026-09-12 15:01 UTCEPSS rescoreEPSS 3.4% · 87th percentile
  16. 2026-09-11 20:23 UTCOSV refresh
  17. 2026-09-11 14:53 UTCEPSS rescoreEPSS 3.4% · 87th percentile
  18. 2026-09-11 09:37 UTCEPSS rescoreEPSS 3.4% · 87th percentile
  19. 2026-09-10 09:34 UTCEPSS rescoreEPSS 3.4% · 87th percentile
  20. 2026-09-08 22:00 UTCEPSS rescoreEPSS 3.4% · 87th percentile
  21. 2026-09-07 16:01 UTCEPSS rescoreEPSS 3.4% · 87th percentile
  22. 2026-09-06 13:47 UTCEPSS rescoreEPSS 3.4% · 87th percentile
  23. 2026-09-04 05:06 UTCEPSS rescoreEPSS 3.4% · 87th percentile
  24. 2026-09-02 14:12 UTCEPSS rescoreEPSS 3.4% · 87th percentile
  25. 2026-09-01 13:54 UTCEPSS rescoreEPSS 3.4% · 87th percentile
  26. 2026-08-30 19:17 UTCEPSS rescoreEPSS 3.4% · 87th percentile
  27. 2026-08-30 01:22 UTCEPSS rescoreEPSS 3.4% · 87th percentile
  28. 2026-08-28 21:41 UTCEPSS rescoreEPSS 3.4% · 87th percentile
  29. 2026-08-27 14:25 UTCEPSS rescoreEPSS 3.4% · 87th percentile
  30. 2026-08-26 14:46 UTCEPSS rescoreEPSS 3.4% · 87th percentile
  31. 2026-08-25 13:49 UTCEPSS rescoreEPSS 3.4% · 87th percentile
  32. 2026-08-23 17:00 UTCEG score recompute
  33. 2026-08-23 00:19 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  34. 2026-08-21 23:49 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  35. 2026-08-21 23:36 UTCEG score recompute
  36. 2026-08-20 22:55 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  37. 2026-08-20 19:00 UTCEG score recompute
  38. 2026-08-19 17:04 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  39. 2026-08-18 13:48 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  40. 2026-08-17 13:47 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  41. 2026-08-16 16:56 UTCEG score recompute
  42. 2026-08-16 14:56 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  43. 2026-08-16 03:33 UTCEG score recompute
  44. 2026-08-16 02:14 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  45. 2026-08-15 01:30 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  46. 2026-08-14 02:06 UTCEG score recompute
  47. 2026-08-13 22:00 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  48. 2026-08-12 15:47 UTCEG score recompute
  49. 2026-08-12 13:51 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  50. 2026-08-11 13:53 UTCEG score recompute
  51. 2026-08-11 00:38 UTCEG score recompute
  52. 2026-08-11 00:00 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  53. 2026-08-09 01:35 UTCEG score recompute
  54. 2026-08-08 16:37 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  55. 2026-08-07 19:33 UTCEG score recompute
  56. 2026-08-06 16:45 UTCEG score recompute
  57. 2026-08-06 13:47 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  58. 2026-08-05 21:20 UTCEG score recompute
  59. 2026-08-05 19:17 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  60. 2026-08-04 15:10 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  61. 2026-08-04 10:39 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  62. 2026-08-03 16:57 UTCEG score recompute
  63. 2026-08-03 10:36 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  64. 2026-08-02 05:16 UTCEG score recompute
  65. 2026-08-02 02:27 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  66. 2026-08-01 17:52 UTCEG score recompute
  67. 2026-08-01 04:16 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  68. 2026-07-30 16:28 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  69. 2026-07-30 01:30 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  70. 2026-07-28 15:36 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  71. 2026-07-27 14:13 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  72. 2026-07-26 14:54 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  73. 2026-07-25 14:18 UTCEPSS rescoreEPSS 2.4% · 82nd percentile
  74. 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.yaml
    Published Jul 15, 2026

    9Router <= 0.4.36 - Unauthenticated RCE

    Open source ↗

Frequently asked(5)

What is CVE-2026-46339?
CVE-2026-46339 is a critical-severity vulnerability; its CVE record was published on May 19, 2026. 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…
When was the CVE record for CVE-2026-46339 published?
The CVE record for CVE-2026-46339 was published on May 19, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of July 16, 2026; the record at its source may have been updated since.
Is CVE-2026-46339 actively exploited?
CVE-2026-46339 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3.4% probability of exploitation in the next 30 days (88th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-46339?
CVE-2026-46339 has a CVSS base score of 10.0 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-46339?
A fix for CVE-2026-46339 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-46339 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-46339

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