CVE-2026-16584

AWS API MCP Server Security Policy Bypass via Startup Failure

Assigner: AMZN
Reserved: 22.07.2026 Published: 23.07.2026 Updated: 23.07.2026

Improper handling of an initialization failure in AWS API MCP Server from 0.2.13 through 1.3.46 might allow an actor to bypass the user-configured security policy and execute AWS API operations that the policy was set to deny or gate. When initialization of the security policy enforcement data fails at server startup, the policy check is skipped for the lifetime of the process. IAM permissions on the configured credentials remain in effect and are unaffected.

To remediate this issue, users should upgrade to version 1.3.47.

Metrics

CVSS Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS Score: 7

Attack Vector	Local	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	Required	Availability Impact	High

CVSS 3.1

CVSS Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 7.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Local	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	Present	Availability	High	Availability	None
Privileges Required	None
User Interaction	Passive

CVSS 4.0

Product Status

Vendor	AWS
Product	aws-api-mcp-server
Versions	Default: unaffected affected from 0.2.13 to 1.3.47 (excl.)

Vendor

AWS

Product

aws-api-mcp-server

Versions

Default: unaffected

affected from 0.2.13 to 1.3.47 (excl.)

References

Problem Types

CWE-455 Non-exit on failed initialization CWE

Impacts