{"answers":{"affected":"","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-100666 exists.","fix":"No fix has been published for CVE-2026-100666 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-100666 is a medium-severity vulnerability in netty, published on 26 Sep 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-2026-100666 and fix it if it is affected.\n\nWhat it is: CVE-2026-100666 is a medium-severity vulnerability in netty, published on 26 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-100666 exists.\n\nAffected product: netty. 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-2026-100666/ (Markdown: https://insights.sbomify.com/CVE-2026-100666/index.md)","id":"CVE-2026-100666","markdown":"https://insights.sbomify.com/CVE-2026-100666/index.md","name":"CVE-2026-100666","record":{"aliases":["DEBIAN-CVE-2026-100666","GHSA-2g6j-r8q9-5hr8","GHSA-jq5g-c66v-g3r2","UBUNTU-CVE-2026-100666"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_read","security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Netty HTTP codec","requires_auth":"none","summary":"Attackers can desynchronize HTTP responses via pipelined requests, causing response splitting and unsafe connection reuse in Netty-based servers.","user_interaction":"not_required","vuln_class":"other"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"VulnCheck","cpe":[],"cvss":{"score":6.9,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-444","name":"Inconsistent Interpretation of HTTP Requests"}],"description":"Netty's HttpServerCodec (io.netty:netty-codec-http) in versions 4.2.0.Final through 4.2.16.Final and in versions up to and including 4.1.136.Final pairs each outbound response with an inbound request by calling pollMethod() once per response, including for 1xx informational responses. If a client pipelines an HTTP/1.1 GET carrying an Expect: 100-continue header followed by a HEAD request, the 100 Continue response consumes the queued GET method, so the subsequent 200 OK for the GET is paired with HEAD and its body is dropped, while the following 200 OK for the HEAD request is written with a body. This desynchronizes HTTP parsing on the connection: the GET entity is never delivered and the HEAD response body is interpreted as the GET body, resulting in response splitting and unsafe connection reuse. Fixed in 4.2.17.Final and 4.1.137.Final.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":false,"headline":"Netty 4.2.0 through 4.2.16 Response Desynchronization via HttpServerCodec","id":"CVE-2026-100666","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"other","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"grav-plugin-login 3.8.7 through 3.9.6 Two-Factor Authentication Bypass","id":"CVE-2026-100667"},"packages":[],"prev":{"headline":"Netty 4.2.11 through 4.2.17 QUIC Hostname Verification Bypass","id":"CVE-2026-100665"},"products":["netty"],"published":"2026-09-26","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-09-30","vendors":["netty"]},"summary":"Attackers can desynchronize HTTP responses via pipelined requests, causing response splitting and unsafe connection reuse in Netty-based servers.","url":"https://insights.sbomify.com/CVE-2026-100666/"}