CVE-2026-16584CWE-455

AWS API MCP Server Security Policy Bypass via Startup Failure

High · published July 23, 2026

CVSS v4.0
7.3
EPSS
0%
Percentile
13.3
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
7.3 · HIGH
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
EPSS
0.00227 · 13.3th percentile
Weakness
CWE-455 · Non-exit on Failed Initialization
Published
2026-07-23T15:34Z
EPSS history
Timeline
  • 23 JUL 15:34Z
    AWS API MCP Server Security Policy Bypass via Startup Failure
    cvelistv5