Upstream information

CVE-2026-34742 at MITRE

Description

The Go MCP SDK used Go's standard encoding/json. Prior to version 1.4.0, the Model Context Protocol (MCP) Go SDK does not enable DNS rebinding protection by default for HTTP-based servers. When an HTTP-based MCP server is run on localhost without authentication with StreamableHTTPHandler or SSEHandler, a malicious website could exploit DNS rebinding to bypass same-origin policy restrictions and send requests to the local MCP server. This could allow an attacker to invoke tools or access resources exposed by the MCP server on behalf of the user in those limited circumstances. This issue has been patched in version 1.4.0.

SUSE information

Overall state of this security issue: Resolved

This issue is currently rated as having important severity.

CVSS v3 Scores
CVSS detail CNA (0b0ca135-0b70-47e7-9f44-1890c2a1c46c) National Vulnerability Database
Base Score 8 8.1
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
Attack Vector Network Network
Attack Complexity High Low
Privileges Required None None
User Interaction Required Required
Scope Changed Unchanged
Confidentiality Impact High High
Integrity Impact High High
Availability Impact None None
CVSSv3 Version 3.1 3.1
CVSS v4 Scores
CVSS detail CNA (GitHub)
Base Score 7.6
Vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/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
Attack Vector Network
Attack Complexity Low
Attack Requirements Present
Privileges Required None
User Interaction Passive
Vulnerable System Confidentiality Impact High
Vulnerable System Integrity Impact High
Vulnerable System Availability Impact None
Subsequent System Confidentiality Impact None
Subsequent System Integrity Impact None
Subsequent System Availability Impact None
CVSSv4 Version 4.0
No SUSE Bugzilla entries cross referenced.

No SUSE Security Announcements cross referenced.

List of released packages

Product(s) Fixed package version(s) References


Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.

Product(s) Source package State
Products under general support and receiving all security fixes.
SUSE Linux Enterprise Server 16.1 govulncheck-vulndb Released
SUSE Linux Enterprise Server for SAP applications 16.1 govulncheck-vulndb Released
Products past their end of life and not receiving proactive updates anymore.
SUSE Linux Enterprise Module for Package Hub 15 SP5 govulncheck-vulndb Affected
SUSE Linux Enterprise Module for Package Hub 15 SP6 govulncheck-vulndb Affected
openSUSE Leap 15.5 govulncheck-vulndb Affected
openSUSE Leap 15.6 govulncheck-vulndb Affected


SUSE Timeline for this CVE

CVE page created: Thu Jul 30 15:06:41 2026
CVE page last modified: Sat Aug 1 11:34:20 2026