CVE-2026-40576

CRITICALNVD 9.49.4
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

This critical-severity CVE scores 9.4 under NVD CVSS v3. EPSS exploit probability: 0.6% (49th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
Trending — 3 sources updated this weekElevated
9.4EG
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: 0.6%CVSS: 9.4Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

excel-mcp-server is a Model Context Protocol server for Excel file manipulation. A path traversal vulnerability exists in excel-mcp-server versions up to and including 0.1.7. When running in SSE or Streamable-HTTP transport mode (the documented way to use this server remotely), an unauthenticated attacker on the network can read, write, and overwrite arbitrary files on the host filesystem by supplying crafted filepath arguments to any of the 25 exposed MCP tool handlers. The server is intended to confine file operations to a directory set by the EXCEL_FILES_PATH environment variable. The function responsible for enforcing this boundary — get_excel_path() — fails to do so due to two independent flaws: it passes absolute paths through without any check, and it joins relative paths without resolving or validating the result. Combined with zero authentication on the default network-facing transport and a default bind address of 0.0.0.0 (all interfaces), this allows trivial remote exploitation. This vulnerability is fixed in 0.1.8.

CVSS v3
9.4
EG Score
9.4CRITICALmedium confidence
EG Risk
73
EG Risk 73/100

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 (value × EchelonGraph’s weight)
Severity94% × 45%
The EG Score, 9.4 of 10.
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 or medium mission impact; Attend at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (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
0.6%
EPSS %ILE
49th
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

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 partial (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)14 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 partial (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

April 21, 2026

Last Modified

April 22, 2026

Advisory Details (1)

Auto-updated Oct 2, 2026
Patch available. Sources: github.
GitHub advisoryMentions a patch (unverified)

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in excel-mcp-server <=0.1.7 · Advisory · haris-musa/excel-mcp-server · GitHub

https://github.com/haris-musa/excel-mcp-server/security/advisories/GHSA-j98m-w3xp-9f56

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
excel-mcp-server0.1.1 ... 0.1.7 (7 versions)
  • every version up to 0.1.8: fixed in 0.1.8
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 15× in last 7d / 32× 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 95 of 183 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. 5 repeat rows among the latest 100 are merged into the row they repeat. The 88 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  2. 2026-10-15 14:46 UTCEG score recompute
  3. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  4. 2026-10-14 09:19 UTCEG score recompute
  5. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  6. 2026-10-13 06:37 UTCEG score recompute
  7. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  8. 2026-10-12 16:09 UTCEG score recompute
  9. 2026-10-11 19:51 UTCEG score recompute
  10. 2026-10-11 17:05 UTCEG score recompute
  11. 2026-10-11 14:31 UTCEG score recompute
  12. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  13. 2026-10-11 05:55 UTCOSV refresh
  14. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  15. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  16. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  17. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  18. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.6% · 49th percentile
  19. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  20. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  21. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  22. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  23. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  24. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.6% · 48th percentile
  25. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.6% · 48th percentile
Show 70 more
  1. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  2. 2026-09-21 17:49 UTCOSV refresh
  3. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  4. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  5. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  6. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  7. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  8. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  9. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  10. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  11. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  12. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  13. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  14. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  15. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  16. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  17. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  18. 2026-09-02 15:01 UTCOSV refresh
  19. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  20. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  21. 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  22. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  23. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  24. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  25. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  26. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  27. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  28. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  29. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  30. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  31. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  32. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  33. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  34. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  35. 2026-08-16 06:17 UTCEG score recompute
  36. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  37. 2026-08-15 02:25 UTCEG score recompute
  38. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  39. 2026-08-14 04:29 UTCEG score recompute
  40. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  41. 2026-08-12 18:40 UTCEG score recompute
  42. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  43. 2026-08-11 16:51 UTCEG score recompute
  44. 2026-08-11 13:43 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  45. 2026-08-11 02:26 UTCEG score recompute
  46. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  47. 2026-08-09 16:49 UTCEG score recompute
  48. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  49. 2026-08-09 03:41 UTCEG score recompute
  50. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  51. 2026-08-07 17:03 UTCEG score recompute
  52. 2026-08-06 17:26 UTCEG score recompute
  53. 2026-08-06 13:46 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  54. 2026-08-05 23:11 UTCEG score recompute
  55. 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  56. 2026-08-04 15:10 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  57. 2026-08-04 10:38 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  58. 2026-08-02 12:47 UTCEG score recompute
  59. 2026-08-02 02:27 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  60. 2026-08-01 04:16 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  61. 2026-07-30 16:28 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  62. 2026-07-30 01:30 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  63. 2026-07-28 15:36 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  64. 2026-07-27 14:13 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  65. 2026-07-26 14:54 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  66. 2026-07-25 14:18 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  67. 2026-07-24 14:17 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  68. 2026-07-23 14:18 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  69. 2026-07-23 03:11 UTCEG score recompute
  70. 2026-07-22 14:08 UTCEPSS rescoreEPSS 0.4% · 31st percentile

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-40576?
CVE-2026-40576 is a critical-severity vulnerability; its CVE record was published on April 21, 2026. excel-mcp-server is a Model Context Protocol server for Excel file manipulation. A path traversal vulnerability exists in excel-mcp-server versions up to and including 0.1.7. When running in SSE or Streamable-HTTP transport mode (the documented way to use this server remotely), an unauthenticated…
When was the CVE record for CVE-2026-40576 published?
The CVE record for CVE-2026-40576 was published on April 21, 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 April 22, 2026; the record at its source may have been updated since.
Is CVE-2026-40576 actively exploited?
CVE-2026-40576 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (49th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-40576?
CVE-2026-40576 has a CVSS v3 base score of 9.4 (NVD).
How do I remediate CVE-2026-40576?
A fix for CVE-2026-40576 is available: update to the fixed version the vendor names in its advisory.

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