CVE-2026-16584 (CVSS 7)

Description

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.

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CVSS v3.1 Score

7.0

HIGH

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

EPSS — Exploit Prediction

0.0013

Probability of exploitation

0.03%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-455 CWE-455

References

Other References

https://aws.amazon.com/security/security-bulletins/2026-063-aws/ https://github.com/awslabs/mcp/security/advisories/GHSA-29w2-fq35-v728 https://pypi.org/project/awslabs.aws-api-mcp-server/1.3.47/

Frequently Asked Questions

What is CVE-2026-16584? +

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. It has a CVSS v3.1 base score of 7.0 (HIGH).

How severe is CVE-2026-16584? +

CVE-2026-16584 has a CVSS v3.1 score of 7.0 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0013, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-16584? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

CVE-2026-16584