{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-6556 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-6556 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-6556 is a critical missing authorization vulnerability in @fastify/express, published on 30 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-6556 and fix it if it is affected.\n\nWhat it is: CVE-2026-6556 is a critical missing authorization vulnerability in @fastify/express, published on 30 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-6556 in the wild and no public exploit code.\n\nAffected product: @fastify/express. No package-level version data is available, so check the vendor advisory linked from the reference page.\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-2026-6556/ (Markdown: https://insights.sbomify.com/CVE-2026-6556/index.md)","id":"CVE-2026-6556","markdown":"https://insights.sbomify.com/CVE-2026-6556/index.md","name":"CVE-2026-6556","record":{"aliases":["GHSA-3wf5-7852-vcfq"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["security_bypass"],"network_reachable":"yes","non_default_config":true,"product_category":"Fastify Express plugin","requires_auth":"none","summary":"Attackers can bypass path-scoped middleware like authentication in prefixed Fastify plugins by using non-string mount paths.","user_interaction":"not_required","vuln_class":"missing_authorization"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"openjs","cpe":[{"product":"fastify\\/express","vendor":"fastify"}],"cvss":{"score":9.1,"severity":"critical","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","version":"3.1"},"cwes":[{"id":"CWE-285","name":"Improper Authorization"}],"description":"@fastify/express versions 4.0.6 and earlier only rewrite the plugin prefix for middleware mount paths when the path argument is a string. Non-string mount paths (arrays of paths and regular expressions) are left unprefixed inside prefixed plugin scopes, so middleware registered with those forms does not match the actual prefixed request path. Applications that use path-scoped middleware for authentication, authorization, rate limiting, or auditing on routes inside a prefixed scope can be bypassed by sending a request to the prefixed route, because Fastify still matches the route but the middleware is skipped. Patches: upgrade to @fastify/express 4.0.7. Workarounds: use string mount paths instead of arrays or regular expressions in prefixed plugins, or register one use call per path.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":false,"headline":"@fastify/express vulnerable to middleware bypass via non-string mount paths in prefixed plugins","id":"CVE-2026-6556","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"missing_authorization","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"Wavlink WL-WN579A3 login.cgi sub_401F80 cross site scripting","id":"CVE-2026-6559"},"packages":[],"prev":{"headline":"ProSolution WP Client \u003c= 2.0.0 - Unauthenticated Arbitrary File Upload via 'files'","id":"CVE-2026-6555"},"products":["@fastify/express"],"published":"2026-06-30","related":[{"cvss_score":9.1,"headline":"@fastify/express vulnerable to middleware path doubling causing authentication bypass in child plugin scopes","id":"CVE-2026-33807","kev_date_added":null,"published":"2026-04-15"},{"cvss_score":9.1,"headline":"@fastify/express has a middleware authentication bypass via URL normalization gaps (duplicate slashes and semicolons)","id":"CVE-2026-33808","kev_date_added":null,"published":"2026-04-15"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"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":"yes","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-06-30","vendors":["@fastify/express"]},"summary":"Attackers can bypass path-scoped middleware like authentication in prefixed Fastify plugins by using non-string mount paths.","url":"https://insights.sbomify.com/CVE-2026-6556/"}