CVE-2026-116684

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Source
https://cve.org/CVERecord?id=CVE-2026-116684
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-116684.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-116684
Aliases
Published
2026-10-27T19:12:24Z
Modified
2026-10-28T02:54:49Z
Severity
  • 6.8 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
Summary
Model Context Protocol Python SDK: Server bearer-token authentication accepts tokens issued for a different resource server
Details

The Model Context Protocol Python SDK is the official Python SDK for Model Context Protocol servers and clients. From 1.10.0 until 1.30.0 and 2.2.0, server-side bearer authentication configured through AuthSettings with token_verifier accepts a valid token issued for another service when the authorization server serves multiple resources and the TokenVerifier does not independently validate the aud audience. This resource-confusion flaw lets a token holder authenticate to the wrong MCP server and exercise that token's resulting access. This issue is fixed in versions 1.30.0 and 2.2.0.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-863"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/116xxx/CVE-2026-116684.json"
}
References

Affected packages

Git / github.com/modelcontextprotocol/python-sdk

Affected ranges

Type
GIT
Repo
https://github.com/modelcontextprotocol/python-sdk
Events
Introduced
dced22344d80d85884df9c26281fdfe0331e9c65
Fixed
8c2fa6eabacde869d75568e33b9d466b58c2f512
Introduced
6f69a3758ebf2ee55ce050f58b470ce11af71133
Fixed
9972c21aa42054fb1450c5fc614761ed11847ec6
Fixed
0c9136841ff092987a20700ff9c2c9789bda2f40
Database specific
Show details 
{
    "extracted_events":  [
        {
            "range":  [
                {
                    "introduced":  "1.10.0"
                },
                {
                    "fixed":  "1.30.0"
                }
            ],
            "source":  "AFFECTED_FIELD",
            "strategy":  "StringRangeExpression"
        },
        {
            "range":  [
                {
                    "introduced":  "2.0.0"
                },
                {
                    "fixed":  "2.2.0"
                }
            ],
            "source":  "AFFECTED_FIELD",
            "strategy":  "StringRangeExpression"
        },
        {
            "range":  [
                {
                    "fixed":  "0c9136841ff092987a20700ff9c2c9789bda2f40"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "range":  [
                {
                    "fixed":  "8c2fa6eabacde869d75568e33b9d466b58c2f512"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "original_tag":  "v1.30.0",
            "range":  [
                {
                    "fixed":  "8c2fa6eabacde869d75568e33b9d466b58c2f512"
                }
            ],
            "source":  "REFERENCES_TAG"
        },
        {
            "original_tag":  "v2.2.0",
            "range":  [
                {
                    "fixed":  "9972c21aa42054fb1450c5fc614761ed11847ec6"
                }
            ],
            "source":  "REFERENCES_TAG"
        }
    ]
}

Affected versions

1.*
1.15.0
v1.*
v1.10.0
v1.10.1
v1.11.0
v1.12.0
v1.12.1
v1.12.2
v1.12.3
v1.12.4
v1.13.0
v1.13.1
v1.14.0
v1.14.1
v1.15.0
v1.16.0
v1.17.0
v1.18.0
v1.19.0
v1.20.0
v1.21.0
v1.21.1
v1.22.0
v1.23.0
v1.23.1
v1.23.2
v1.23.3
v1.24.0
v1.25.0
v1.26.0
v1.27.0
v1.27.1
v1.27.2
v1.28.0
v1.28.1
v1.29.0
v1.29.1
v2.*
v2.0.0
v2.1.0
v2.1.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-116684.json"