CVE-2026-86541

HIGHPre-NVD 8.38.3—
EchelonGraph scoreHIGH confidence

Score 8.3 from GitHub Security Advisory (severity: HIGH) published 2026-09-08. the CNA's CVSS baseline 8.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — 3 sources updated this week
8.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 8.3Exploit: None knownExposed: 0

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

knowns versions before 0.30.0 contain a path traversal vulnerability in the handleCodeReplace() function that allows attackers to overwrite arbitrary files outside the project root. Attackers can supply absolute paths or relative paths containing directory traversal sequences to write malicious content to sensitive files like shell startup scripts or SSH configuration files.

CVSS v3
8.3
EG Score
8.3(high)
EG Risk
53(Track)
EG Risk 53/100SSVC: Track

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
Severity83% × 45%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
54%
KEV
Not listed

Published

September 7, 2026

Last Modified

September 24, 2026

Advisory Details (5)

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

knowns before 0.30.0 Path Traversal via code.replace MCP action | Advisories | VulnCheck

https://www.vulncheck.com/advisories/knowns-before-0.30.0-path-traversal-via-code-replace-mcp-action
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 a2c98fc5c313 (knowns-dev/knowns)

Fix landed in knowns-dev/knowns commit a2c98fc5c313 — awaiting tagged release

https://github.com/knowns-dev/knowns/commit/a2c98fc5c313463576c9348beeec6a74ddd7333b
generic

knowns/internal/mcp/handlers/code.go at v0.29.1 · knowns-dev/knowns · GitHub

https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/mcp/handlers/code.go#L588-L646
github Patch Available

Authorization Bypass and Path Traversal in code.replace allows Arbitrary File Overwrite · Advisory · knowns-dev/knowns · GitHub

https://github.com/knowns-dev/knowns/security/advisories/GHSA-f539-xgc6-xw7q

Vendor Advisories for CVE-2026-86541(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 25× in last 7d / 71× 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. 2026-09-25 01:48 UTCGHSA enrichment
  2. 2026-09-24 14:21 UTCEG score recompute
  3. 2026-09-24 14:21 UTCGHSA enrichment
  4. 2026-09-24 14:04 UTCEPSS rescore
  5. 2026-09-24 02:22 UTCEG score recompute
  6. 2026-09-24 02:22 UTCGHSA enrichment
  7. 2026-09-23 17:54 UTCEPSS rescore
  8. 2026-09-23 14:55 UTCGHSA enrichment
  9. 2026-09-23 03:29 UTCGHSA enrichment
  10. 2026-09-22 16:02 UTCEG score recompute
  11. 2026-09-22 16:02 UTCGHSA enrichment
  12. 2026-09-22 16:01 UTCEPSS rescore
  13. 2026-09-22 04:35 UTCEG score recompute
  14. 2026-09-22 04:35 UTCGHSA enrichment
  15. 2026-09-21 21:09 UTCEPSS rescore
  16. 2026-09-21 17:07 UTCGHSA enrichment
  17. 2026-09-21 05:05 UTCGHSA enrichment
  18. 2026-09-20 17:15 UTCGHSA enrichment
  19. 2026-09-20 05:44 UTCGHSA enrichment
  20. 2026-09-19 18:17 UTCEG score recompute
  21. 2026-09-19 18:17 UTCGHSA enrichment
  22. 2026-09-19 06:50 UTCEG score recompute
  23. 2026-09-19 06:50 UTCGHSA enrichment
  24. 2026-09-18 19:28 UTCEPSS rescore
  25. 2026-09-18 19:15 UTCGHSA enrichment
Show 46 more
  1. 2026-09-18 07:47 UTCGHSA enrichment
  2. 2026-09-17 20:20 UTCEG score recompute
  3. 2026-09-17 20:20 UTCGHSA enrichment
  4. 2026-09-17 19:32 UTCEPSS rescore
  5. 2026-09-17 05:50 UTCGHSA enrichment
  6. 2026-09-16 18:19 UTCEG score recompute
  7. 2026-09-16 18:19 UTCGHSA enrichment
  8. 2026-09-16 14:09 UTCEPSS rescore
  9. 2026-09-16 06:16 UTCEG score recompute
  10. 2026-09-16 06:16 UTCGHSA enrichment
  11. 2026-09-16 05:15 UTCEPSS rescore
  12. 2026-09-15 18:50 UTCGHSA enrichment
  13. 2026-09-15 07:23 UTCEG score recompute
  14. 2026-09-15 07:23 UTCGHSA enrichment
  15. 2026-09-15 03:12 UTCEPSS rescore
  16. 2026-09-15 03:12 UTCEPSS rescore
  17. 2026-09-14 19:56 UTCGHSA enrichment
  18. 2026-09-14 08:29 UTCGHSA enrichment
  19. 2026-09-13 21:02 UTCEG score recompute
  20. 2026-09-13 21:02 UTCGHSA enrichment
  21. 2026-09-13 09:35 UTCGHSA enrichment
  22. 2026-09-12 22:08 UTCEG score recompute
  23. 2026-09-12 22:08 UTCGHSA enrichment
  24. 2026-09-12 10:40 UTCGHSA enrichment
  25. 2026-09-11 23:13 UTCEG score recompute
  26. 2026-09-11 23:13 UTCGHSA enrichment
  27. 2026-09-11 14:53 UTCEPSS rescore
  28. 2026-09-11 14:53 UTCEPSS rescore
  29. 2026-09-11 11:18 UTCEG score recompute
  30. 2026-09-11 11:18 UTCGHSA enrichment
  31. 2026-09-11 03:51 UTCGHSA enrichment
  32. 2026-09-10 16:24 UTCEG score recompute
  33. 2026-09-10 16:24 UTCGHSA enrichment
  34. 2026-09-10 15:27 UTCEG score recompute
  35. 2026-09-10 15:27 UTCGHSA enrichment
  36. 2026-09-10 06:34 UTCGHSA enrichment
  37. 2026-09-09 19:07 UTCGHSA enrichment
  38. 2026-09-09 07:39 UTCEG score recompute
  39. 2026-09-09 07:39 UTCGHSA enrichment
  40. 2026-09-08 22:01 UTCEPSS rescore
  41. 2026-09-08 20:12 UTCGHSA enrichment
  42. 2026-09-08 11:04 UTCEG score recompute
  43. 2026-09-08 11:03 UTCGHSA enrichment
  44. 2026-09-07 23:35 UTCEG score recompute
  45. 2026-09-07 23:07 UTCEG score recompute
  46. 2026-09-07 23:06 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-86541?
CVE-2026-86541 is a high vulnerability published on September 7, 2026. knowns versions before 0.30.0 contain a path traversal vulnerability in the handleCodeReplace() function that allows attackers to overwrite arbitrary files outside the project root. Attackers can supply absolute paths or relative paths containing directory traversal sequences to write malicious…
When was CVE-2026-86541 disclosed?
CVE-2026-86541 was first published in the National Vulnerability Database 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-2026-86541 actively exploited?
CVE-2026-86541 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 46.4% of all scored CVEs.
What is the CVSS score of CVE-2026-86541?
CVE-2026-86541 has a CVSS v4.0 base score of 8.3 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-86541?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-86541, 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.

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