7.5

CVE-2026-104850: modelcontextprotocol typescript-sdk

CVSS: 7.5v3.1HighAwaiting analysis
AliasesCGA-7w3x-vvc9-9qv7CGA-9v2q-2hwx-v39wCGA-cv8x-3c5g-mw6c
Published 06-10-2026Last modified 06-10-2026
Open JSON

Vulnerability summary

CVE-2026-104850 is a high (CVSS 7.5) vulnerability in modelcontextprotocol typescript-sdk. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 6.6% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.18%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 06-10-2026
    PublishedVulnerability first disclosed.
  2. 06-10-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.18%

Chance of exploitation in the next 30 days

Percentile

7%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

07-10-202619-10-2026
EPSS score
0.18%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard23 products
  • commercial-gitlab-rails-ee-19.1< 19.1.7-r3
  • commercial-gitlab-rails-ee-19.2< 19.2.7-r1
  • commercial-gitlab-rails-ee-19.3< 19.3.3-r1
  • commercial-gitlab-rails-ee-19.4< 19.4.1-r1
  • commercial-gitlab-rails-ee-fips-19.1All versions (No fix recorded)
@modelcontextprotocol2 products
  • client≥ 2.0.0, < 2.2.0
  • sdk≥ 1.12.0, < 1.31.0
Wolfi2 products
  • langfuse-3< 3.225.11-r8
  • langfuse-3-worker< 3.225.11-r8
Modelcontextprotocol1 product

4 vendors · 28 products

References

7 links