CVE-2026-42559
Essential information
- Published
- 14/05/2026 15:16
- Modified
- 14/05/2026 17:19
- Author
- —
- Creator
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- CVSS
- 8.8 HIGH (v3.1)
- CISA KEV
- No
- CWE
- —
- CVSS vector
-
—
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H—
CVSS metrics
- Access vector
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- Access complexity
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- Authentication
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- Confidentiality impact
- —
- Integrity impact
- —
- Availability impact
- —
- Exploitability
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- Remediation level
- —
- Report confidence
- —
- Temporal score
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- Attack vector
- NETWORK
- Attack complexity
- LOW
- Privileges required
- NONE
- User interaction
- REQUIRED
- Scope
- UNCHANGED
- Confidentiality impact
- HIGH
- Integrity impact
- HIGH
- Availability impact
- HIGH
- Exploit code maturity
- —
- Remediation level
- —
- Report confidence
- —
- Temporal score
- —
- Attack vector
- —
- Attack complexity
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- Attack requirements
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- Privileges required
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- User interaction
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- Confidentiality (V)
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- Confidentiality (S)
- —
- Integrity (V)
- —
- Integrity (S)
- —
- Availability (V)
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- Availability (S)
- —
- Exploit maturity
- —
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.
NVD status
- Status
- Deferred — CVE has been recently published to the CVE List and has been received by the NVD.
- Source
- [email protected]
- NVD
- View on NVD
Affected products (CPE)
| Product | CPE |
|---|---|
| rust / rmcp | cpe:2.3:a:rust:rmcp:*:*:*:*:*:*:*:* |