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RUSTSEC-2026-0140

HighCVSS 8.8 / 10
Published May 12, 2026·Last modified May 13, 2026
Affected Components(0)

No affected components available

Description

dynoxide's MCP HTTP transport was vulnerable to DNS rebinding via its transitive rmcp dependency, plus a related cross-origin CSRF gap.

A malicious web page could make the user's browser send requests to a local dynoxide mcp --http or dynoxide serve --mcp server with a non-loopback Host header, which the server would then process. The Host check alone did not close a related cross-origin CSRF vector: a page could fetch the loopback endpoint with mode: 'no-cors', and the Host header would match while the Origin header went unchecked.

Affected MCP write tools include put_item, update_item, delete_item, create_table, and batch_write_item.

The stdio transport (dynoxide mcp without --http) is not affected.

Patches

dynoxide 0.9.13 closes both vectors:

  • Upgrades rmcp from 1.1.1 to 1.6.0 (which ships a default Host-header allowlist).
  • Sets explicit allowed_hosts and allowed_origins on StreamableHttpServerConfig.
Risk Scores
Base Score
8.8

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. The attacker needs the user to perform some action, like clicking a link. The impact is confined to the system where the vulnerability exists. There is a high impact on the confidentiality of the information. There is a high impact on the integrity of the data. There is a high impact on the availability of the system.

Threat Intelligence
8.1

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS
0.21%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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High severity
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