{"answers":{"affected":"3 open source packages ship an affected version, including github.com/modelcontextprotocol/registry. It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-44429 exists.","fix":"Upgrade github.com/modelcontextprotocol/registry to 1.7.7 or later.","what":"CVE-2026-44429 is a medium-severity cross-site scripting vulnerability in modelcontextprotocol registry, published on 14 May 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-44429 and fix it if it is affected.\n\nWhat it is: CVE-2026-44429 is a medium-severity cross-site scripting vulnerability in modelcontextprotocol registry, published on 14 May 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-44429 exists.\n\nAffected packages and fixed versions:\n- github.com/modelcontextprotocol/registry (Go): affected all versions; fixed in 1.7.7\n- github.com/modelcontextprotocol/registry (Go): affected all versions; fixed in 1.7.7\n- github.com/modelcontextprotocol/registry (Go): affected all versions; fixed in 1.7.7\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-2026-44429/ (Markdown: https://insights.sbomify.com/CVE-2026-44429/index.md)","id":"CVE-2026-44429","markdown":"https://insights.sbomify.com/CVE-2026-44429/index.md","name":"CVE-2026-44429","record":{"aliases":["GHSA-rqv2-m695-f8j4","GO-2026-5637"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["code_execution","account_takeover"],"network_reachable":"yes","non_default_config":false,"product_category":"MCP Registry","requires_auth":"low_privilege","summary":"Attackers can inject malicious scripts into the MCP Registry homepage via the websiteUrl field, potentially compromising user sessions and executing code in browsers.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"mcp_registry","vendor":"lfprojects"}],"cvss":{"score":5.1,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:N/SI:L/SA:L","version":"4.0"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"},{"id":"CWE-116","name":"Improper Encoding or Escaping of Output"}],"description":"The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. Prior to 1.7.7, the public catalogue UI served at GET / (file internal/api/handlers/v0/ui_index.html) is vulnerable to stored cross-site scripting via the server.websiteUrl field of any published server.json. Server-side validation in internal/validators/validators.go (validateWebsiteURL) only checks that the URL parses, is absolute, and uses the https scheme; it does not reject quote characters. Client-side, the value is interpolated into a double-quoted href attribute via innerHTML, using a homegrown escapeHtml helper that performs the standard textContent → innerHTML round-trip. Per the HTML serialisation algorithm, that round-trip encodes only \u0026, \u003c, \u003e and U+00A0 inside text nodes — it does not encode \" or '. A literal \" in websiteUrl therefore breaks out of the href attribute, allowing arbitrary on* event handlers to be appended to the same \u003ca\u003e element. The Content-Security-Policy on / is script-src 'self' 'unsafe-inline' https://cdn.tailwindcss.com, so the injected event handlers execute. Any user able to obtain a publish token (e.g. via POST /v0/auth/github-at with their own GitHub account, or POST /v0/auth/none on a deployment that has anonymous auth enabled) can plant a poisoned record visible to every visitor of the registry homepage. This vulnerability is fixed in 1.7.7.","ecosystems":["Go"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"MCP Registry: Stored XSS in catalogue UI via attribute-quote breakout in publisher-controlled `websiteUrl`","id":"CVE-2026-44429","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Go","product":null,"products":[],"type":"xss","year":"2026"},"n_packages":3,"n_references":1,"next":{"headline":"MCP Registry has an unauthenticated SSRF: HTTP namespace verification dials 6to4 / NAT64 / site-local IPv6 addresses, bypassing private-address allowlist","id":"CVE-2026-44430"},"packages":[{"ecosystem":"Go","fixed":["1.7.7"],"introduced":["0"],"last_affected":[],"package":"github.com/modelcontextprotocol/registry","purl":null,"source":"GHSA-rqv2-m695-f8j4"},{"ecosystem":"Go","fixed":["1.7.7"],"introduced":["0"],"last_affected":[],"package":"github.com/modelcontextprotocol/registry","purl":"pkg:golang/github.com/modelcontextprotocol/registry","source":"GHSA-rqv2-m695-f8j4"},{"ecosystem":"Go","fixed":["1.7.7"],"introduced":["0"],"last_affected":[],"package":"github.com/modelcontextprotocol/registry","purl":"pkg:golang/github.com/modelcontextprotocol/registry","source":"GO-2026-5637"}],"prev":{"headline":"MCP Registry: GitHub OIDC tokens replayable across registry deployments due to shared audience","id":"CVE-2026-44428"},"products":["registry"],"published":"2026-05-14","related":[{"cvss_score":6.3,"headline":"MCP Registry has an unauthenticated SSRF: HTTP namespace verification dials 6to4 / NAT64 / site-local IPv6 addresses, bypassing private-address allowlist","id":"CVE-2026-44430","kev_date_added":null,"published":"2026-05-14"},{"cvss_score":2.1,"headline":"MCP Registry: GitHub OIDC tokens replayable across registry deployments due to shared audience","id":"CVE-2026-44428","kev_date_added":null,"published":"2026-05-14"}],"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":"attribution","licence":"CC BY 4.0","name":"Go Vulnerability Database","prefix":"GO"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-15","vendors":["modelcontextprotocol"]},"summary":"Attackers can inject malicious scripts into the MCP Registry homepage via the websiteUrl field, potentially compromising user sessions and executing code in browsers.","url":"https://insights.sbomify.com/CVE-2026-44429/"}