AWS API MCP Server OAuth Token Audience Validation Bypass

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-115413
StatePUBLISHED
AssignerAMZN
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-27 19:17:10 UTC
Updated2026-10-28 14:10:17 UTC
DescriptionMissing token audience validation in the OAuth authentication mode of AWS API MCP Server before version 1.6.0 might allow local users to run AWS operations with the server's configured AWS credentials via an access token issued to another application by the same identity provider. To remediate this issue, users should upgrade to version 1.6.0 and configure the expected token audience or client ID for the server.

Risk And Classification

Primary CVSS: v4.0 7.3 HIGH from ff89ba41-3aa1-4d27-914a-91399e9639e5

CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.000970000 probability, percentile 0.007210000 (date 2026-10-28)

Problem Types: CWE-346 | CWE-346 CWE-346 Origin validation error

VersionSourceTypeScoreSeverityVector
4.0ff89ba41-3aa1-4d27-914a-91399e9639e5Secondary7.3HIGHCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS7.3HIGHCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
3.1ff89ba41-3aa1-4d27-914a-91399e9639e5Secondary7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
3.1CNACVSS7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v4.0 Breakdown

Attack Vector
Local
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
Low
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 Breakdown

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

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA AWS Aws-api-mcp-server affected 1.3.0 1.6.0 custom Not specified

References

ReferenceSourceLinkTags
pypi.org/project/awslabs.aws-api-mcp-server/1.6.0 ff89ba41-3aa1-4d27-914a-91399e9639e5 pypi.org
github.com/awslabs/mcp/security/advisories/GHSA-4prq-p2x5-w9fh ff89ba41-3aa1-4d27-914a-91399e9639e5 github.com
aws.amazon.com/security/security-bulletins/2026-152-aws ff89ba41-3aa1-4d27-914a-91399e9639e5 aws.amazon.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

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