{"answers":{"affected":"3 open source packages ship an affected version, including cowboy.","exploited":"There is no known exploitation of CVE-2026-8466 in the wild and no public exploit code.","fix":"Upgrade cowboy to 2.15.0 or later.","what":"CVE-2026-8466 is a high-severity denial of service vulnerability in ninenines cowboy, published on 13 May 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-2026-8466 and fix it if it is affected.\n\nWhat it is: CVE-2026-8466 is a high-severity denial of service vulnerability in ninenines cowboy, published on 13 May 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-2026-8466 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- cowboy (Hex): affected from 2.0.0; fixed in 2.15.0\n- cowboy (Hex): affected from 2.0.0; fixed in 2.15.0\n- cowboy (Hex): affected from 2.0.0; fixed in 2.15.0\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-2026-8466/ (Markdown: https://insights.sbomify.com/CVE-2026-8466/index.md)","id":"CVE-2026-8466","markdown":"https://insights.sbomify.com/CVE-2026-8466/index.md","name":"CVE-2026-8466","record":{"aliases":["AZL-88266","DEBIAN-CVE-2026-8466","EEF-CVE-2026-8466","GHSA-jfc2-q6qh-g5x8","UBUNTU-CVE-2026-8466"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Erlang HTTP server","requires_auth":"none","summary":"An unauthenticated attacker can cause denial of service in Cowboy by sending multipart requests that trigger unbounded memory accumulation during header parsing.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"EEF","cpe":[],"cvss":{"score":8.2,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-770","name":"Allocation of Resources Without Limits or Throttling"}],"description":"Allocation of Resources Without Limits or Throttling vulnerability in ninenines cowboy allows denial of service via unbounded buffer accumulation in multipart header parsing.\n\ncowboy_req:read_part/3 in src/cowboy_req.erl accumulates incoming request bytes into a Buffer binary with no upper-bound check. When cow_multipart:parse_headers/2 returns more or {more, Buffer2}, the function reads up to Length bytes (default 64 KB) from the request body and recurses with the enlarged buffer. There is no equivalent of the byte_size(Acc) \u003e Length guard present in the sibling function read_part_body/4. An unauthenticated attacker can send a multipart/form-data request whose body never yields a complete header section — for example, a body that never contains the advertised boundary delimiter, or one whose header lines never contain \\r\\n\\r\\n — and force the server process to accumulate memory linearly with the bytes the protocol layer is willing to deliver. A handful of concurrent such uploads is sufficient to exhaust BEAM memory.\n\nThis issue affects cowboy from 2.0.0 before 2.15.0.","ecosystems":["Hex"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"Unbounded buffer accumulation in multipart header parsing causes denial of service in cowboy","id":"CVE-2026-8466","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Hex","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":3,"n_references":3,"next":{"headline":"Unauthenticated remote code execution via HEEx template injection in phoenix_storybook playground","id":"CVE-2026-8467"},"packages":[{"ecosystem":"Hex","fixed":["2.15.0"],"introduced":["2.0.0"],"last_affected":[],"package":"cowboy","purl":"pkg:hex/cowboy","source":"EEF-CVE-2026-8466"},{"ecosystem":"Hex","fixed":["2.15.0"],"introduced":["2.0.0"],"last_affected":[],"package":"cowboy","purl":null,"source":"GHSA-jfc2-q6qh-g5x8"},{"ecosystem":"Hex","fixed":["2.15.0"],"introduced":["2.0.0"],"last_affected":[],"package":"cowboy","purl":"pkg:hex/cowboy","source":"GHSA-jfc2-q6qh-g5x8"}],"prev":{"headline":"Path traversal in Neuron Soft Golem OEE MES","id":"CVE-2026-8464"},"products":["cowboy"],"published":"2026-05-13","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"Erlang Ecosystem Foundation","prefix":"EEF"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-14","vendors":["ninenines"]},"summary":"An unauthenticated attacker can cause denial of service in Cowboy by sending multipart requests that trigger unbounded memory accumulation during header parsing.","url":"https://insights.sbomify.com/CVE-2026-8466/"}