Is CVE-2026-33946 actively exploited?

CVE-2026-33946 has no public evidence of in-the-wild exploitation as of 2026-04-02.

What is the CVSS score for CVE-2026-33946?

CVE-2026-33946 has a CVSS score of 8.2 (HIGH severity). Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/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.

How do I patch CVE-2026-33946?

Patch guidance is available from lfprojects security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-33946.

Which products are affected by CVE-2026-33946?

1 product: lfprojects mcp ruby sdk.

Fix CVE-2026-33946 - HIGH lfprojects mcp ruby sdk

Description

MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to version 0.9.2, the Ruby SDK's streamable_http_transport.rb implementation contains a session hijacking vulnerability. An attacker who obtains a valid session ID can completely hijack the victim's Server-Sent Events (SSE) stream and intercept all real-time data. Version 0.9.2 contains a patch.

CVSS Metrics

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/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
Attack Vector: network
Complexity: low
Privileges: none
User Action: none
Confidentiality: undefined
Integrity: undefined
Availability: undefined
Weaknesses: CWE-384 CWE-639 CWE-384

Metadata

Primary Vendor: LFPROJECTS
Published: 3/27/2026
Last Modified: 4/2/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

lfprojects : mcp_ruby_sdk

Remediation Guidance

Executive Summary

Cite this page

CVE-2026-33946. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2026-33946

View on NIST NVD

CVE-2026-33946 vulnerability