CVE-2026-86540

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-09-08. The CNA's CVSS baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — 3 sources updated this weekElevated
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 7.8Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

knowns versions before 0.30.0 fail to validate the settings.lsp.languages binary field in project configuration files, allowing attackers to execute arbitrary binaries by crafting a malicious .knowns/config.json file. When a repository with a crafted configuration is opened, the unvalidated binary path is executed twice under the user's account without any verification.

CVSS v3
7.8
EG Score
7.8HIGHmedium confidence
EG Risk
51
EG Risk 51/100CISA SSVC

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
Severity78% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low, Track* at medium and Attend at high mission impact.
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
0.2%
EPSS %ILE
10th
KEV
Not listed

CISA SSVCTrack 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 no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 7, 2026

Last Modified

September 24, 2026

Advisory Details (6)

Auto-updated Sep 7, 2026
Patch available. Sources: github, github_commit, github_release.
generic

knowns before 0.30.0 Arbitrary Code Execution via LSP Binary | Advisories | VulnCheck

https://www.vulncheck.com/advisories/knowns-before-0.30.0-arbitrary-code-execution-via-lsp-binary
github_release Patch Available

v0.30.0

Patch available: knowns-dev/knowns v0.30.0

https://github.com/knowns-dev/knowns/releases/tag/v0.30.0
github_commit

commit d3989829fb50 (knowns-dev/knowns)

Fix landed in knowns-dev/knowns commit d3989829fb50 — awaiting tagged release

https://github.com/knowns-dev/knowns/commit/d3989829fb5095666d23d005b2f78a082832a396
generic

knowns/internal/models/config.go at v0.29.1 · knowns-dev/knowns · GitHub

https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/models/config.go#L205-L216
generic

knowns/internal/lsp/detect.go at v0.29.1 · knowns-dev/knowns · GitHub

https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/lsp/detect.go#L128-L157
githubMentions a patch (unverified)

OS Command Injection via Insecure LSP Binary Path Config in .knowns/config.json · Advisory · knowns-dev/knowns · GitHub

https://github.com/knowns-dev/knowns/security/advisories/GHSA-mc52-mwq4-vfx3

Vendor Advisories for CVE-2026-86540(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
knowns—
  • every version up to 0.30.0: fixed in 0.30.0
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 18× in last 7d / 106× 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.

Showing the most recent 100 of 123 total refreshes for this CVE.

  1. 2026-10-10 20:00 UTCEPSS rescore
  2. 2026-10-09 22:41 UTCEG score recompute
  3. 2026-10-09 20:07 UTCEPSS rescore
  4. 2026-10-09 00:49 UTCEG score recompute
  5. 2026-10-08 17:13 UTCEPSS rescore
  6. 2026-10-08 09:56 UTCEG score recompute
  7. 2026-10-07 23:48 UTCEPSS rescore
  8. 2026-10-06 22:16 UTCEG score recompute
  9. 2026-10-06 15:18 UTCEPSS rescore
  10. 2026-10-06 10:53 UTCGHSA enrichment
  11. 2026-10-05 22:54 UTCEG score recompute
  12. 2026-10-05 22:54 UTCGHSA enrichment
  13. 2026-10-05 17:44 UTCEPSS rescore
  14. 2026-10-05 11:12 UTCGHSA enrichment
  15. 2026-10-04 23:34 UTCEG score recompute
  16. 2026-10-04 23:34 UTCGHSA enrichment
  17. 2026-10-04 23:22 UTCEPSS rescore
  18. 2026-10-04 12:12 UTCGHSA enrichment
  19. 2026-10-04 00:51 UTCEG score recompute
  20. 2026-10-04 00:51 UTCGHSA enrichment
  21. 2026-10-03 12:22 UTCGHSA enrichment
  22. 2026-10-03 00:21 UTCEG score recompute
  23. 2026-10-03 00:21 UTCGHSA enrichment
  24. 2026-10-02 12:47 UTCGHSA enrichment
  25. 2026-10-02 01:19 UTCEG score recompute
Show 75 more
  1. 2026-10-02 01:19 UTCGHSA enrichment
  2. 2026-10-01 19:50 UTCEPSS rescore
  3. 2026-10-01 13:58 UTCGHSA enrichment
  4. 2026-10-01 02:37 UTCGHSA enrichment
  5. 2026-09-30 15:16 UTCEG score recompute
  6. 2026-09-30 15:16 UTCGHSA enrichment
  7. 2026-09-30 15:04 UTCEPSS rescore
  8. 2026-09-30 02:27 UTCEG score recompute
  9. 2026-09-30 02:27 UTCGHSA enrichment
  10. 2026-09-29 09:43 UTCGHSA enrichment
  11. 2026-09-28 22:18 UTCEG score recompute
  12. 2026-09-28 22:18 UTCGHSA enrichment
  13. 2026-09-28 13:52 UTCEPSS rescore
  14. 2026-09-28 10:44 UTCGHSA enrichment
  15. 2026-09-27 23:14 UTCEG score recompute
  16. 2026-09-27 23:14 UTCGHSA enrichment
  17. 2026-09-27 13:48 UTCEPSS rescore
  18. 2026-09-27 11:52 UTCGHSA enrichment
  19. 2026-09-27 00:31 UTCEG score recompute
  20. 2026-09-27 00:31 UTCGHSA enrichment
  21. 2026-09-26 15:59 UTCEPSS rescore
  22. 2026-09-26 12:57 UTCGHSA enrichment
  23. 2026-09-26 01:36 UTCEG score recompute
  24. 2026-09-26 01:36 UTCGHSA enrichment
  25. 2026-09-25 13:39 UTCGHSA enrichment
  26. 2026-09-25 02:15 UTCGHSA enrichment
  27. 2026-09-24 14:53 UTCEG score recompute
  28. 2026-09-24 14:53 UTCGHSA enrichment
  29. 2026-09-24 14:04 UTCEPSS rescore
  30. 2026-09-24 11:21 UTCGHSA enrichment
  31. 2026-09-24 00:00 UTCEG score recompute
  32. 2026-09-24 00:00 UTCGHSA enrichment
  33. 2026-09-23 17:54 UTCEPSS rescore
  34. 2026-09-23 12:38 UTCGHSA enrichment
  35. 2026-09-23 01:16 UTCEG score recompute
  36. 2026-09-23 01:16 UTCGHSA enrichment
  37. 2026-09-22 16:01 UTCEPSS rescore
  38. 2026-09-22 13:54 UTCGHSA enrichment
  39. 2026-09-22 02:33 UTCEG score recompute
  40. 2026-09-22 02:33 UTCGHSA enrichment
  41. 2026-09-21 21:09 UTCEPSS rescore
  42. 2026-09-21 15:12 UTCGHSA enrichment
  43. 2026-09-21 03:51 UTCEG score recompute
  44. 2026-09-21 03:51 UTCGHSA enrichment
  45. 2026-09-20 20:16 UTCEPSS rescore
  46. 2026-09-20 16:29 UTCGHSA enrichment
  47. 2026-09-20 05:08 UTCGHSA enrichment
  48. 2026-09-19 17:46 UTCEG score recompute
  49. 2026-09-19 17:46 UTCGHSA enrichment
  50. 2026-09-19 06:24 UTCEG score recompute
  51. 2026-09-19 06:24 UTCGHSA enrichment
  52. 2026-09-18 19:28 UTCEPSS rescore
  53. 2026-09-18 19:03 UTCGHSA enrichment
  54. 2026-09-18 07:42 UTCGHSA enrichment
  55. 2026-09-17 20:20 UTCEG score recompute
  56. 2026-09-17 20:20 UTCGHSA enrichment
  57. 2026-09-17 19:32 UTCEPSS rescore
  58. 2026-09-17 05:44 UTCGHSA enrichment
  59. 2026-09-16 18:19 UTCEG score recompute
  60. 2026-09-16 18:19 UTCGHSA enrichment
  61. 2026-09-16 14:09 UTCEPSS rescore
  62. 2026-09-16 05:39 UTCEG score recompute
  63. 2026-09-16 05:39 UTCGHSA enrichment
  64. 2026-09-16 05:15 UTCEPSS rescore
  65. 2026-09-15 18:18 UTCGHSA enrichment
  66. 2026-09-15 06:47 UTCEG score recompute
  67. 2026-09-15 06:47 UTCGHSA enrichment
  68. 2026-09-15 03:12 UTCEPSS rescore
  69. 2026-09-15 03:12 UTCEPSS rescore
  70. 2026-09-14 19:25 UTCGHSA enrichment
  71. 2026-09-14 08:03 UTCGHSA enrichment
  72. 2026-09-13 20:41 UTCEG score recompute
  73. 2026-09-13 20:41 UTCGHSA enrichment
  74. 2026-09-13 09:19 UTCGHSA enrichment
  75. 2026-09-12 21:58 UTCEG score recompute

Related CVEs(same product + same CWE)

Same product

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npm:knowns

Frequently asked(5)

What is CVE-2026-86540?
CVE-2026-86540 is a high vulnerability published on September 7, 2026. knowns versions before 0.30.0 fail to validate the settings.lsp.languages binary field in project configuration files, allowing attackers to execute arbitrary binaries by crafting a malicious .knowns/config.json file. When a repository with a crafted configuration is opened, the unvalidated binary…
When was CVE-2026-86540 disclosed?
CVE-2026-86540 was first published on September 7, 2026, with the most recent update on September 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-86540 actively exploited?
CVE-2026-86540 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (10th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-86540?
CVE-2026-86540 has a CVSS base score of 7.8 (the CNA's own assessment, by vulncheck; NVD's own analysis pending).
How do I remediate CVE-2026-86540?
A fix for CVE-2026-86540 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-86540 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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