LIVE · cybersecurity feed
Live wire
ASOS Breach Reveals the Risks in Customer-Facing SaaSUnpatched AhsayCBS flaws exploited to deploy webshells, mine cryptoAI Training Critical as Governance Challenges GrowUS Disrupts Chinese State-Sponsored Hacking ToolsCitrix warns admins to patch new NetScaler RCE flaw immediatelyCisco Patches a Dozen Critical VulnerabilitiesCisco warns of critical flaws allowing Nexus switch takeoverCVE-2026-21589 · Exploitation attempts against critical Atlassian flaw have begun (CVE-2026-21589)Cyber experts call on CISA to create mandatory federal OT rulesGremlin Foresight AI finds system weaknesses and verifies the fixes
cve recordhigh

CVE-2026-42559

Published
CVSS8.8
Severityhigh
WeaknessCWE-346
ExploitedNot in CISA KEV

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

Description

RMCP is an official Rust SDK for the Model Context Protocol. Prior to version 1.4.0, the rmcp crate's Streamable HTTP server transport (crates/rmcp/src/transport/streamable_http_server/) did not validate the incoming Host header. This allowed a malicious public website, via a DNS rebinding attack, to send authenticated requests to an MCP server running on the victim's loopback or private-network interface. This vulnerability is fixed in 1.4.0.

References

← Back to the CVE Tracker

Our coverage of CVE-2026-42559

No stories yet. This page updates automatically when we publish reporting that references CVE-2026-42559.