Unbounded body accumulation in HTTP/3 response loop in hackney_CVE-2026-47077

{
    "lastseen": "",
    "description": "Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding. hackney_h3:await_response_loop/6 accumulates the HTTP/3 response body in memory without any size cap. The after Timeout clause is a per-message inactivity timer that resets on every received chunk, housekeeping message, or settings frame \u2014 it is not a wall-clock deadline. A malicious HTTP/3 server that emits one small chunk every Timeout - 1 ms with Fin = false and never sends a final frame keeps the loop alive indefinitely while the accumulation buffer grows linearly without bound, eventually exhausting the BEAM process heap and causing an out-of-memory condition.\n\nThis issue affects hackney: from 2.0.0 before 4.0.1.",
    "published": "2026-05-25T14:00:42.217Z",
    "modified": "2026-05-25T14:00:42.217Z",
    "type": "cve",
    "title": "Unbounded body accumulation in HTTP/3 response loop in hackney",
    "source": "EEF",
    "references": "https://github.com/benoitc/hackney/security/advisories/GHSA-jq4m-q6p2-8gwc\nhttps://cna.erlef.org/cves/CVE-2026-47077.html\nhttps://osv.dev/vulnerability/EEF-CVE-2026-47077\nhttps://github.com/benoitc/hackney/commit/3d25f9fea26c90609de9d64366fedfe5065413bc",
    "id": "CVE-2026-47077",
    "bulletinFamily": "",
    "cwe": [
        "CWE-400"
    ],
    "cvelist": null,
    "sourceData": "benoitc hackney 2.0.0\nbenoitc hackney 0334af206d5099fdf510ed9eda18e34396f065ad",
    "sourceHref": "",
    "cvss": {
        "score": 8.2,
        "severity": "HIGH",
        "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"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "hackney",
    "version": "2.0.0",
    "vendor": "benoitc",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}