{"id":"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.","aliases":["EEF-CVE-2026-48862","GHSA-g586-ccqf-7x4r"],"modified":"2026-06-18T03:54:53.292106332Z","published":"2026-06-02T14:15:10.591Z","database_specific":{"cna_assigner":"EEF","cwe_ids":["CWE-770"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48862.json","unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"65c6394d05a1b8aa4a7461708c3aa173e8d7a5cf"},{"fixed":"70b97b6a5209fb288b0e04d8e657dda26c59de67"}]}]},"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"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/elixir-mint/mint","events":[{"introduced":"8d3152c6409146b861b800a1fc804fff24f4a226"},{"fixed":"d1c8c5cafdfe5d3fdf1e42a2d0594d26855a12a1"},{"fixed":"70b97b6a5209fb288b0e04d8e657dda26c59de67"}],"database_specific":{"source":["DESCRIPTION","REFERENCES"],"extracted_events":[{"introduced":"0.2.0"},{"fixed":"1.9.0"}]}}],"versions":["v1.8.0","v1.7.1","v1.7.0","v1.6.2","v1.6.1","v1.6.0","v1.5.2","v1.5.1","v1.5.0","v1.4.2","v1.4.1","v1.4.0","v1.3.0","v1.2.1","v1.2.0","v1.1.0","v1.0.0","v0.5.0","v0.4.0","v0.2.1","v0.2.0"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-48862.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"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"}]}