HTTP/1.1 chunked request bodies made of 1-byte chunks amplify memory use in Bandit

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  "url": "https://www.cve.org/CVERecord?id=CVE-2026-111101",
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  "payload": {
    "kind": "advisory",
    "title": "HTTP/1.1 chunked request bodies made of 1-byte chunks amplify memory use in Bandit",
    "summary": "Allocation of Resources Without Limits or Throttling vulnerability in the HTTP/1.1 chunked body reader of mtrudel bandit allows an unauthenticated remote attacker to exhaust server memory and CPU via a request body made of many 1-byte chunks. The chunked reader in lib/bandit/http1/socket.ex keeps every chunk as its own list cell and binary term until IO.iodata_to_binary/1 joins them, and nothing limits the number of chunks. The :length option of read_body/2 counts only data bytes, so tiny chunks cost far more memory than their payload: 48 MB of 1-byte chunks grew one handler process to about 500 MB and took about 6 s of CPU. The route does not need to read the body, because on keep-alive connections ensure_completed/1 drains unread bodies through the same reader. This issue affects bandit: from 0.1.0 before 1.14.0.",
    "evidence": "cve:CVE-2026-111101",
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            "Automatable": "NOT_DEFINED",
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            "valueDensity": "NOT_DEFINED",
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      "affected": [
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            "cpe:2.3:a:mtrudel:bandit:*:*:*:*:*:*:*:*"
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      "modified": "2026-10-26T15:35:51.401Z",
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      "references": [
        "https://github.com/mtrudel/bandit/security/advisories/GHSA-jwh3-j29h-qfmw",
        "https://cna.erlef.org/cves/CVE-2026-111101.html",
        "https://osv.dev/vulnerability/EEF-CVE-2026-111101",
        "https://github.com/mtrudel/bandit/commit/7201270c34b90f6c9e15c0386c2bb802c0c72ab4",
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  "published_at": "2026-10-26T13:31:48.184+00:00"
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