Dashboard / CVE-2026-33946

CVE-2026-33946

HIGH
MEDIUM Priority: 0.04 BB Relevance: 76/100
Published: 2026-03-27 Modified: 2026-10-26 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction Conf. Impact

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: X
AT: Present
VC: High
VI: None
VA: None

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.

Weakness Classification (2)

Affected Software (1)

VendorProductVersion
lfprojects mcp_ruby_sdk < 0.9.2

References & Advisories (8)

Bug Bounty Relevance

76 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

8.2 / 10.0 v4.0
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

EPSS — Exploitation Probability

0.47%
Raw Score 0.004740
Percentile 40.9%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00474
2026-10-28
0.00474

Intelligence Sources

nvd ref →

External Links