CVE-2026-125271

AWS API MCP Server Security Policy Bypass via Incorrect Operation Name Normalization

Published Nov 10, 2026 CVSS 4.0 · 8.5 High EPSS < 1% KEV · Not listed
Description
Incorrect normalization of operation names in the custom security policy enforcement in awslabs aws-api-mcp-server before 1.5.1 might allow an actor to execute AWS API operations across AWS services that the operator's security policy was configured to deny or require elicitation for, via calls to operations whose names contain consecutive capital letters.



To remediate this issue, users should upgrade to version 1.5.1.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Description Incorrect normalization of operation names in the custom security policy enforcement in awslabs aws-api-mcp-server before 1.5.1 might allow an actor to execute AWS API operations across AWS services that the operator's security policy was configured to deny or require elicitation for, via calls to operations whose names contain consecutive capital letters. To remediate this issue, users should upgrade to version 1.5.1.
Title AWS API MCP Server Security Policy Bypass via Incorrect Operation Name Normalization
First Time appeared Aws
Aws aws-api-mcp-server
Weaknesses CWE-1025
CWE-863
CPEs cpe:2.3:a:aws:aws-api-mcp-server:*:*:*:*:*:*:*:*
Vendors & Products Aws
Aws aws-api-mcp-server
References
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 8.5, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
AMZN
Published
Updated
Nov 10, 2026, 4:35 PM
Reserved
Nov 9, 2026, 6:28 PM
Status
Awaiting Analysis
Published
Nov 10, 2026, 5:17 PM
Modified
Nov 12, 2026, 7:24 PM