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CVE-2026-104850

HIGH 7.5

Published 2026-10-06 · Last modified 2026-10-06

MCP TypeScript SDK is the official TypeScript SDK for Model Context Protocol servers and clients. Starting in version 1.12.0 and prior to versions 1.31.0 and 2.2.0, the SDK's OAuth client support let the MCP server a client connected to decide which authorization server received the client's OAuth credentials. Stored and pre-provisioned credentials were not bound to the authorization server they belong to. A malicious or compromised MCP server could name its own authorization server in its protected resource metadata. Without any user interaction, the client would send that server the `refresh_token` and `client_secret` stored from an earlier sign-in (1.x), or the configured `client_secret` or signed assertion of a bundled non-interactive provider (1.x and 2.x). Only those applications that use the SDK as an MCP client over HTTP with an `authProvider`: your own `OAuthClientProvider`, or the bundled `ClientCredentialsProvider`, `PrivateKeyJwtProvider`, `StaticPrivateKeyJwtProvider` or (2.x) `CrossAppAccessProvider` and that may connect to an MCP server the owners does not fully trust while holding credentials for a legitimate authorization server are affected. `@modelcontextprotocol/sdk` 1.31.0 (1.x) and `@modelcontextprotocol/client` 2.2.0 (2.x) patch the issue. A workaround for those who cannot upgrade is available. 2.0.0 and 2.1.0 already accept `expectedIssuer`. On 1.x, the only workaround is to connect OAuth-enabled clients only to MCP servers you trust.

ELEVATED IMPACT

Severe if exploited (CVSS 7.5), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.2%chance of exploitation in 30 days · 13th percentile

○ In CISA KEV ○ Catalogued PoC

Impact if exploited

7.5CVSS 3.1 · HIGH

  • ConfidentialityHigh
  • IntegrityNone
  • AvailabilityNone

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ✓Privileges: No account or privileges required
  • ✓User interaction: No user interaction needed
  • ✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept

No public PoC is currently catalogued.

Search for new PoCs

Search GitHub now — results may be empty or unverified.

Tracked sources are checked daily for recent CVEs, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.

Data snapshot:

Affected

Vendors Modelcontextprotocol

Products Typescript Sdk

Weakness (CWE)

  • CWE-345: : Insufficient Verification of Data Authenticity
  • CWE-522: : Insufficiently Protected Credentials

CVSS vector

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

References and research data (JSON)

Packages and version ranges

Each advisory describes its own package and affected ranges. A boundary applies to that range; it is not a universal upgrade recommendation.

  • @modelcontextprotocol/sdk npm

    pkg:npm/%40modelcontextprotocol/sdk

    SEMVER range
    • Introduced version (included): 1.12.0
    • Fixed boundary (excluded): 1.31.0
    Additional upstream package constraints
    {
  "database": {
    "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-6qxp-vccf-f47h/GHSA-6qxp-vccf-f47h.json"
  }
}
    GitHub Advisory Database · GHSA-6qxp-vccf-f47h · Updated 2026-10-06T15:46:47.143033168Z
  • @modelcontextprotocol/client npm

    pkg:npm/%40modelcontextprotocol/client

    SEMVER range
    • Introduced version (included): 2.0.0
    • Fixed boundary (excluded): 2.2.0
    Additional upstream package constraints
    {
  "database": {
    "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-6qxp-vccf-f47h/GHSA-6qxp-vccf-f47h.json"
  }
}
    GitHub Advisory Database · GHSA-6qxp-vccf-f47h · Updated 2026-10-06T15:46:47.143033168Z

Vendor product assessments

  • mta/mta-solution-server-rhel9 as a component of Migration Toolkit for Applications 8 · known affected

    Vendor assessment for this product only.

    pkg:oci/mta-solution-server-rhel9@sha256:cff08d56550c3d272072ff72f1bac9f1f05065e4eb9810ebf9e0c6696bc544a9?repository_url=registry.redhat.io/mta/mta-solution-server-rhel9

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Affected
    Red Hat · CVE-2026-104850 · Updated 2026-10-23T10:31:40+00:00
  • ansible-automation-platform-27/mcp-server-rhel9 as a component of Red Hat Ansible Automation Platform 2 · known affected

    Vendor assessment for this product only.

    pkg:oci/mcp-server-rhel9@sha256:e4d3dae1bff12fb56c2b660c2d748ad6993a611d59263260e40f02b45ca4d3b8?repository_url=registry.redhat.io/ansible-automation-platform-27/mcp-server-rhel9

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Affected
    Red Hat · CVE-2026-104850 · Updated 2026-10-23T10:31:40+00:00
  • ansible-automation-platform-tech-preview/mcp-server-rhel9 as a component of Red Hat Ansible Automation Platform 2 · known affected

    Vendor assessment for this product only.

    pkg:oci/mcp-server-rhel9@sha256:8a5bb8b5a3751aec8fc24ee67ea6f920559bfc3aeac3338c675f45c923e42f3c?repository_url=registry.redhat.io/ansible-automation-platform-tech-preview/mcp-server-rhel9

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Affected
    Red Hat · CVE-2026-104850 · Updated 2026-10-23T10:31:40+00:00
  • rhoai/odh-workbench-codeserver-datascience-cpu-py312-rhel9 as a component of Red Hat OpenShift AI (RHOAI) · known affected

    Vendor assessment for this product only.

    pkg:oci/odh-workbench-codeserver-datascience-cpu-py312-rhel9@sha256:7b24ef41420bc79e19ff6349bb4760b2834bdc245eeb0b9191a8e77d90515a3a?repository_url=registry.redhat.io/rhoai/odh-workbench-codeserver-datascience-cpu-py312-rhel9

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Affected
    Red Hat · CVE-2026-104850 · Updated 2026-10-23T10:31:40+00:00
  • devspaces/code-rhel9 as a component of Red Hat OpenShift Dev Spaces · known affected

    Vendor assessment for this product only.

    pkg:oci/code-rhel9@sha256:2a80ac1e2c7f68dd5b726d49b5a660959de0036d992356bb742eb08349563dec?repository_url=registry.redhat.io/devspaces/code-rhel9

    • workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
    • none available: Affected
    Red Hat · CVE-2026-104850 · Updated 2026-10-23T10:31:40+00:00
  • goose as a component of Red Hat Enterprise Linux 10 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not in execute path

    pkg:rpm/redhat/goose

    Red Hat · CVE-2026-104850 · Updated 2026-10-23T10:31:40+00:00
  • goose.src as a component of Red Hat Enterprise Linux 10 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not in execute path

    pkg:rpm/redhat/goose?arch=src

    Red Hat · CVE-2026-104850 · Updated 2026-10-23T10:31:40+00:00
  • grafana as a component of Red Hat Enterprise Linux 10 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/grafana

    Red Hat · CVE-2026-104850 · Updated 2026-10-23T10:31:40+00:00
  • grafana-selinux as a component of Red Hat Enterprise Linux 10 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/grafana-selinux

    Red Hat · CVE-2026-104850 · Updated 2026-10-23T10:31:40+00:00
  • grafana.src as a component of Red Hat Enterprise Linux 10 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/grafana?arch=src

    Red Hat · CVE-2026-104850 · Updated 2026-10-23T10:31:40+00:00
  • goose as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/goose

    Red Hat · CVE-2026-104850 · Updated 2026-10-23T10:31:40+00:00
  • goose.src as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/goose?arch=src

    Red Hat · CVE-2026-104850 · Updated 2026-10-23T10:31:40+00:00
  • grafana12.4.src as a component of Red Hat Hardened Images · known not affected

    Vendor assessment for this product only.

    Reason: component not present

    pkg:rpm/redhat/[email protected]?arch=src

    Red Hat · CVE-2026-104850 · Updated 2026-10-23T10:31:40+00:00
  • grafana13.1.src as a component of Red Hat Hardened Images · known not affected

    Vendor assessment for this product only.

    Reason: component not present

    pkg:rpm/redhat/[email protected]?arch=src

    Red Hat · CVE-2026-104850 · Updated 2026-10-23T10:31:40+00:00
  • grafana13.2.src as a component of Red Hat Hardened Images · known not affected

    Vendor assessment for this product only.

    Reason: component not present

    pkg:rpm/redhat/[email protected]?arch=src

    Red Hat · CVE-2026-104850 · Updated 2026-10-23T10:31:40+00:00

All CVSS metrics

  • HIGH 7.5 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
  • HIGH 7.5 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References

Advisories

Technical & other

Sources: NVD · CVE.org · EPSS