{"id":"CVE-2026-48862","aliases":["EEF-CVE-2026-48862","GHSA-g586-ccqf-7x4r"],"url":"https://o3.security/vulnerability/CVE-2026-48862","summary":"Unbounded conn.streams growth in Mint HTTP/2 client via unenforced PUSH_PROMISE concurrency","details":"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":"2026-08-12T03:51:49.141922762Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Hex","name":"mint","fixedVersion":"1.9.0"}],"fix":{"url":"https://github.com/elixir-mint/mint/commit/70b97b6a5209fb288b0e04d8e657dda26c59de67","label":"elixir-mint/mint@70b97b6"},"references":[{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-48862.html"},{"type":"WEB","url":"https://github.com"},{"type":"WEB","url":"https://osv.dev/vulnerability/EEF-CVE-2026-48862"},{"type":"WEB","url":"https://repo.hex.pm"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48862.json"},{"type":"ADVISORY","url":"https://github.com/elixir-mint/mint/security/advisories/GHSA-g586-ccqf-7x4r"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48862"},{"type":"FIX","url":"https://github.com/elixir-mint/mint/commit/70b97b6a5209fb288b0e04d8e657dda26c59de67"},{"type":"PACKAGE","url":"https://github.com/elixir-mint/mint"},{"type":"PACKAGE","url":"https://github.com/elixir-mint/mint.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:49.141922762Z"}}