{"answers":{"affected":"","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-100663 exists.","fix":"No fix has been published for CVE-2026-100663 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-100663 is a high-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-2026-100663 and fix it if it is affected.\n\nWhat it is: CVE-2026-100663 is a high-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-2026-100663 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-2026-100663/ (Markdown: https://insights.sbomify.com/CVE-2026-100663/index.md)","id":"CVE-2026-100663","markdown":"https://insights.sbomify.com/CVE-2026-100663/index.md","name":"CVE-2026-100663","record":{"aliases":["GHSA-jgph-cgq3-c627","GHSA-qmrm-mg2w-2mpw","UBUNTU-CVE-2026-100663"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Netty HTTP/3 codec","requires_auth":"none","summary":"Attackers can bypass tunnel allow-lists and egress policies in Netty-based HTTP/1-to-HTTP/3 proxies by sending malformed CONNECT requests.","user_interaction":"not_required","vuln_class":"security_feature_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"VulnCheck","cpe":[],"cvss":{"score":8.7,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-20","name":"Improper Input Validation"}],"description":"Netty's HTTP/3 codec (io.netty:netty-codec-http3) from 4.2.2.Final through 4.2.17.Final does not special-case HTTP/1 CONNECT authority-form request-targets when converting HTTP/1 messages to HTTP/3 in HttpConversionUtil.toHttp3Headers. The authority-form target (e.g., \"CONNECT trusted.example:443\") is parsed as a URI, so its host is emitted as :scheme, :path is set to \"/\", and the HTTP/1 Host header is used as :authority; if no Host header is present the CONNECT target is dropped. In a Netty-based HTTP/1-to-HTTP/3 proxy or gateway, a remote client can send a CONNECT request whose Host header names a different authority than the request-target, producing a malformed HTTP/3 CONNECT whose tunnel :authority is attacker-controlled. This can bypass tunnel allow-lists, egress policy, backend selection, or audit controls that validate the HTTP/1 CONNECT request-target before forwarding over HTTP/3. The issue is fixed in 4.2.18.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 HTTP/1 CONNECT authority-form mistranslated to malformed HTTP/3","id":"CVE-2026-100663","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"security_feature_bypass","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"Netty 4.2.2 through 4.2.17 HTTP/1 Host Header Authority Confusion","id":"CVE-2026-100664"},"packages":[],"prev":{"headline":"Netty HTTP/3 QPACK encoder-stream unbounded memory exhaustion DoS","id":"CVE-2026-100662"},"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":"no","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-09-28","vendors":["netty"]},"summary":"Attackers can bypass tunnel allow-lists and egress policies in Netty-based HTTP/1-to-HTTP/3 proxies by sending malformed CONNECT requests.","url":"https://insights.sbomify.com/CVE-2026-100663/"}