{"answers":{"affected":"8 open source packages ship an affected version, including dynoxide-rs, rmcp and dynoxide.","exploited":"There is no known exploitation of CVE-2026-42559 in the wild and no public exploit code.","fix":"Upgrade dynoxide-rs to 0.9.13 or later.","what":"CVE-2026-42559 is a high-severity server-side request forgery vulnerability in modelcontextprotocol rust-sdk, published on 14 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-42559 and fix it if it is affected.\n\nWhat it is: CVE-2026-42559 is a high-severity server-side request forgery vulnerability in modelcontextprotocol rust-sdk, published on 14 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-42559 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- dynoxide-rs (crates.io): affected from 0.9.3; fixed in 0.9.13\n- dynoxide-rs (crates.io): affected from 0.9.3; fixed in 0.9.13\n- dynoxide-rs (crates.io): affected from 0.9.3; fixed in 0.9.13\n- rmcp (crates.io): affected all versions; fixed in 1.4.0\n- rmcp (crates.io): affected all versions; fixed in 1.4.0\n- rmcp (crates.io): affected from 0.0.0-0; fixed in 1.4.0\n- dynoxide (npm): affected from 0.9.3; fixed in 0.9.13\n- dynoxide (npm): affected from 0.9.3; fixed in 0.9.13\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-42559/ (Markdown: https://insights.sbomify.com/CVE-2026-42559/index.md)","id":"CVE-2026-42559","markdown":"https://insights.sbomify.com/CVE-2026-42559/index.md","name":"CVE-2026-42559","record":{"aliases":["GHSA-89vp-x53w-74fx","GHSA-fvh2-gm75-j4j7","RUSTSEC-2026-0140","RUSTSEC-2026-0189"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_read","security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Rust MCP SDK","requires_auth":"none","summary":"Attackers can use DNS rebinding to send authenticated requests to local MCP servers via the Rust SDK's HTTP transport.","user_interaction":"required","vuln_class":"ssrf"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":8.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-350","name":"Reliance on Reverse DNS Resolution for a Security-Critical Action"},{"id":"CWE-346","name":"Origin Validation Error"}],"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.","ecosystems":["crates.io","npm"],"exploits":{"exploitdb":0,"first_seen":"2026-09-06","github_poc":1,"max_poc_stars":0,"metasploit":0,"nuclei":0,"refs":[{"date":"2026-09-06T22:33:24Z","kind":"github_poc","ref":"https://github.com/joaovicdev/EXPLOIT-CVE-2026-42559","stars":0,"title":"Docker lab + Python PoC for CVE-2026-42559 - DNS rebinding via unvalidated Host header in the rmcp (Rust MCP SDK) Streamable HTTP server transport"}],"tier":"poc_unverified"},"has_fix":true,"headline":"RMCP: DNS rebinding vulnerability in rmcp Streamable HTTP server transport","id":"CVE-2026-42559","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"crates.io","product":null,"products":[],"type":"ssrf","year":"2026"},"n_packages":8,"n_references":5,"next":{"headline":"auth: Patreon provider assigns the same local user ID to every authenticated Patreon account, enabling cross‑user impersonation","id":"CVE-2026-42560"},"packages":[{"ecosystem":"crates.io","fixed":["0.9.13"],"introduced":["0.9.3"],"last_affected":[],"package":"dynoxide-rs","purl":null,"source":"GHSA-fvh2-gm75-j4j7"},{"ecosystem":"crates.io","fixed":["0.9.13"],"introduced":["0.9.3"],"last_affected":[],"package":"dynoxide-rs","purl":"pkg:cargo/dynoxide-rs","source":"GHSA-fvh2-gm75-j4j7"},{"ecosystem":"crates.io","fixed":["0.9.13"],"introduced":["0.9.3"],"last_affected":[],"package":"dynoxide-rs","purl":"pkg:cargo/dynoxide-rs","source":"RUSTSEC-2026-0140"},{"ecosystem":"crates.io","fixed":["1.4.0"],"introduced":["0"],"last_affected":[],"package":"rmcp","purl":null,"source":"GHSA-89vp-x53w-74fx"},{"ecosystem":"crates.io","fixed":["1.4.0"],"introduced":["0"],"last_affected":[],"package":"rmcp","purl":"pkg:cargo/rmcp","source":"GHSA-89vp-x53w-74fx"},{"ecosystem":"crates.io","fixed":["1.4.0"],"introduced":["0.0.0-0"],"last_affected":[],"package":"rmcp","purl":"pkg:cargo/rmcp","source":"RUSTSEC-2026-0189"},{"ecosystem":"npm","fixed":["0.9.13"],"introduced":["0.9.3"],"last_affected":[],"package":"dynoxide","purl":null,"source":"GHSA-fvh2-gm75-j4j7"},{"ecosystem":"npm","fixed":["0.9.13"],"introduced":["0.9.3"],"last_affected":[],"package":"dynoxide","purl":"pkg:npm/dynoxide","source":"GHSA-fvh2-gm75-j4j7"}],"prev":{"headline":"Xibo Vulnerable to Stored XSS and Iframe Sandbox Escape via Data Connector Script in DataSet","id":"CVE-2026-42558"},"products":["rust-sdk"],"published":"2026-05-14","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"open","licence":"CC0 1.0","name":"RustSec","prefix":"RUSTSEC"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-05-14","vendors":["modelcontextprotocol"]},"summary":"Attackers can use DNS rebinding to send authenticated requests to local MCP servers via the Rust SDK's HTTP transport.","url":"https://insights.sbomify.com/CVE-2026-42559/"}