CVE detail
CVE-2026-34742
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.
Buzz score
Why this CVE is surfacing
This all-time snapshot uses the same composite formula as Trending across a 30-year evidence window, rather than a current rolling window.
Buzz score components · mention 22.0 · diversity 13.0 · KEV 0.0 · OTX 0.0 · PoC 0.0
Why it matters now
Mention timeline
- Total mentions
- 0
- within the 30d window
- Peak daily
- 0
- highest bucket
Evidence
Source links by recency
8 source links · newest first
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34742.jsonsecurity.access.redhat.com
No excerpt available.
Vendor Advisorysecurity.access.redhat.comApr 2, 2026, 7:21 PM - https://bugzilla.redhat.com/show_bug.cgi?id=2454608bugzilla.redhat.com
No excerpt available.
Exploitbugzilla.redhat.comApr 2, 2026, 7:21 PM - https://access.redhat.com/security/cve/CVE-2026-34742access.redhat.com
No excerpt available.
Exploitaccess.redhat.comApr 2, 2026, 7:21 PM - https://access.redhat.com/errata/RHSA-2026:21772access.redhat.com
No excerpt available.
Exploitaccess.redhat.comApr 2, 2026, 7:21 PM No excerpt available.
Exploitgithub.comApr 2, 2026, 7:21 PMNo excerpt available.
Exploitgithub.comApr 2, 2026, 7:21 PMNo excerpt available.
Exploitgithub.comApr 2, 2026, 7:21 PM- https://github.com/modelcontextprotocol/go-sdk/commit/67bd3f2e2b53ce11a16db8d976cdb8ff1e986b6dgithub.com
No excerpt available.
Exploitgithub.comApr 2, 2026, 7:21 PM
Exploit code
Public exploit repository references
Public PoC repositories are third-party, potentially unsafe artifacts. Treat their code as untrusted and use it only on authorized systems in an isolated, least-privilege environment. cvebuzz does not execute the code or verify that an exploit works.
0 repository references · best confidence N/A · max 0 stars
Related records
Similar CVEs
6 related CVEs with shared weakness or product evidence
- CVE-2025-59321CVSS 9.8 · Critical
CPSD CryptoPro Secure Disk for Bitlocker before v7.7.4 contains a default TPM PCR policy that fails to consider the system boot state. This allows the TPM to be unsealed via an un…
- CVE-2026-33921CVSS 4.8 · Medium
The Windows installer deployed Npcap leaving its access restriction option at the insecure default value, so the driver was accessible to every local user of the host instead of b…
- CVE-2026-63563CVSS 6.9 · Medium
Sharp and Toshiba Tec MFPs (multifunction printers) for a certain market have been shipped with the user authentication feature disabled in the initial configuration. When used wi…
- CVE-2026-62416CVSS 6.9 · Medium
Network Scanner Tool and Network Scanner Tool Lite provided by Sharp Corporation, with the initial configuration, require no authentication and accept files unlimitedly. When the…
- CVE-2026-16504CVSS 9.8 · Critical
Deployment of the VPS.org one-click Zulip template deploys a hardcoded application signing key, a default database password ("zulip"), and DISABLE_HTTPS=True.
- CVE-2026-16503CVSS 9.1 · Critical
Deployment of the VPS.org one-click Supabase template deploys a PostgreSQL instance that is published on all interfaces (0.0.0.0:5432) with a default database password set to "pos…