Is CVE-2026-27124 actively exploited?

No active exploitation of CVE-2026-27124 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-27124 be exploited remotely?

Yes. CVE-2026-27124 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-27124?

CVE-2026-27124 has a CVSS score of 8.2 (HIGH).

HOME VULNERABILITIESCVE-2026-27124

HIGH

CVE-2026-27124

CWE-441Published: April 3, 2026· Updated: Apr 7, 2026

8.2

CVSS v3.1

EPSS:0.05%probability of exploitation in 30 daysPercentile:15.3th

Official Description

FastMCP is the standard framework for building MCP applications. Prior to version 3.2.0, while testing the GitHubProvider OAuth integration, which allows authentication to a FastMCP MCP server via a FastMCP OAuthProxy using GitHub OAuth, it was discovered that the FastMCP OAuthProxy does not properly validate the user's consent upon receiving the authorization code from GitHub. In combination with GitHub’s behavior of skipping the consent page for previously authorized clients, this introduces a Confused Deputy vulnerability. This issue has been patched in version 3.2.0.

NVD Source

Technical Analysis

CVE-2026-27124 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionNone

ScopeX

Impact

Confidentiality

Integrity

Availability

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/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