CVE-2026-108953 json
mac-shell-mcp before 2.0.0 OS Command Injection via execute_command Arguments
published 28d ago modified 24d ago also EUVD-2026-97360
- cvss
- 7.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 55%
- public exploits
- 0
- none known
Summary
mac-shell-mcp before 2.0.0 contains an OS command injection vulnerability that allows MCP clients to bypass the command whitelist by injecting shell metacharacters into execute_command arguments. Attackers or malicious prompts can call a safe command such as pwd with arguments like ';' to run forbidden commands as the server user without approval.
Patch / fix
Is CVE-2026-108953 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 27d ago
Exploit prediction
0.75% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.5 | CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| CNA | 3.1 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| CNA | 4.0 | 8.5 | CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- cfdude mac-shell-mcp
Classification
- Weakness
-
- CWE-78 Improper Neutralization of Special Elements used in an OS Command
References
-
github.com
/cfdude/mac-shell-mcp/commit/932ce733cde07bb30b1f186303e6692dbb5d087a
patch
-
github.com
/cfdude/mac-shell-mcp/issues/45
issue-tracking
-
github.com
/cfdude/mac-shell-mcp/blob/1c1708201abb7a18c83075e1bf933e7a92cbeb9f/src/services/command-service.ts#L257-L340
technical-description
-
github.com
/cfdude/mac-shell-mcp
product
-
vulncheck.com
/advisories/mac-shell-mcp-before-2.0.0-os-command-injection-via-execute-command-arguments
third-party-advisory
Sources
- CVE List CVE-2026-108953
- NVD CVE-2026-108953
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