CVE-2026-40576

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.46% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 40.0% of scored records. A rank, not a probability.

NVD base score

9.4 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H

NVD analysis status

Deferred. NVD last modified this record on 2026-10-26.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-04-21 16:35Z6 MO AGO

Last updated

2026-04-21 16:50Z6 MO AGO

Reserved

2026-04-14

Assigning CNA

GitHub_M

Record state

PUBLISHED

Severity

Critical (CVSS 9.4)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H

Weaknesses

• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')Base

Data version

5.2

Document digest

a26ec246e55de1cf3ff0b459b1505074a44ac0781bc74d7f997b5c447061b9f6

• github.comhttps://github.com/haris-musa/excel-mcp-server/security/advisories/GHSA-j98m-w3xp-9f56x_refsource_CONFIRM