Unbounded conn.streams growth in Mint HTTP/2 client via unenforced PUSH_PROMISE concurrency_CVE-2026-48862

{
    "lastseen": "",
    "description": "Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint Mint allows attacker-controlled HTTP/2 servers to exhaust memory in a Mint client via PUSH_PROMISE flooding.\n\nIn lib/mint/http2.ex, Mint.HTTP2.decode_push_promise_headers_and_add_response/5 inserts a :reserved_remote entry into conn.streams for every promised stream ID. The neighbouring Mint.HTTP2.assert_valid_promised_stream_id/2 only verifies that the promised ID is even and not already present; client_settings.max_concurrent_streams is not consulted at promise time. The concurrency cap is only checked when the response HEADERS for the promised stream arrive, so a server that emits PUSH_PROMISE frames and withholds the matching HEADERS never trips that check.\n\nHTTP/2 server push is accepted by default (client_settings.enable_push defaults to true). A single long-lived HTTP/2 connection to a hostile server lets that server pin one conn.streams entry per PUSH_PROMISE frame it sends, with no upper bound, until the client process runs out of memory.\n\nThis issue affects mint: from 0.2.0 before 1.9.0.",
    "published": "2026-06-02T14:15:10.591Z",
    "modified": "2026-06-02T14:15:10.591Z",
    "type": "cve",
    "title": "Unbounded conn.streams growth in Mint HTTP/2 client via unenforced PUSH_PROMISE concurrency",
    "source": "EEF",
    "references": "https://github.com/elixir-mint/mint/security/advisories/GHSA-g586-ccqf-7x4r\nhttps://cna.erlef.org/cves/CVE-2026-48862.html\nhttps://osv.dev/vulnerability/EEF-CVE-2026-48862\nhttps://github.com/elixir-mint/mint/commit/70b97b6a5209fb288b0e04d8e657dda26c59de67",
    "id": "CVE-2026-48862",
    "bulletinFamily": "",
    "cwe": [
        "CWE-770"
    ],
    "cvelist": null,
    "sourceData": "elixir-mint mint 0.2.0\nelixir-mint mint 65c6394d05a1b8aa4a7461708c3aa173e8d7a5cf",
    "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": "mint",
    "version": "0.2.0",
    "vendor": "elixir-mint",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}