Incomplete input validation in AWS MCP Server run_script tool
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
AWS MCP Server's run_script tool checks Python code against an incomplete list of disallowed inputs (CWE-184). An authenticated remote user with low privileges can run arbitrary code within their own isolated session by submitting a crafted script.
Written with Claude Haiku 5.5 from the sources below · 2026-11-02
Description from the CNA
An incomplete list of disallowed inputs in the Python code validator of the run_script tool in AWS MCP Server might allow an authenticated remote user to execute arbitrary code within their own isolated session environment via a crafted script. AWS fixed this issue service-side. No customer action is required.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
The sources list no fixed version for AWS MCP Server. AWS fixed this issue service-side, and no customer action is required.
Written with Claude Haiku 5.5 from the sources below · 2026-11-02
Timeline
- 2026-10-23 Threatist record created from CVE-2026-115845
- 2026-10-23 Alias added: GHSA-jmwp-36mq-x645
- 2026-11-02 CISA SSVC decision points changed
References
More AWS vulnerabilities
- TI-2026-23989 crypto: algif_aead - Revert to operating out-of-place KEVCVSS 3.1HIGH 7.8
- TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
- TI-2024-18648 Amazon AWS Amplify CLI before 12.10.1 incorrectly configures the role trust policy of IAM… CVSS 3.1CRITICAL 9.8
- TI-2024-05929 Openssh: regresshion - race condition in ssh allows rce/dos CVSS 3.1HIGH 8.1
- TI-2025-03847 Input validation issue in AWS Amplify Studio UI component properties CVSS 4.0CRITICAL 9.0
- TI-2026-11603 HTTP/2 Stream Parser Confusion Body-Inspection Bypass in Amazon CloudFront with AWS WAF CVSS 4.0HIGH 7.9
Sources
- CVE-2026-115845 · CVE Program
- CVE-2026-115845 · NVD
- FIRST EPSS
- GHSA-jmwp-36mq-x645 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences