HTTP/2 CONTINUATION flood in Mint client via unbounded header-block accumulation

{
  "id": "53235b76da19d89462d106aa005190cca94d7a718b6c75cf33e80f25782f3fba",
  "url": "https://osv.dev/vulnerability/CVE-2026-49754",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "HTTP/2 CONTINUATION flood in Mint client via unbounded header-block accumulation",
    "summary": "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 (HTTP/2 CONTINUATION flood). When Mint's HTTP/2 receive path observes a HEADERS frame without the END_HEADERS flag, the unparsed header-block fragment is parked in conn.headers_being_processed, and every subsequent CONTINUATION frame on that stream is appended to the accumulator. Nothing in the receive path caps the accumulator: there is no per-stream size limit, no CONTINUATION frame-count limit, and max_header_list_size is only enforced on outgoing requests, never on inbound header blocks (its default is :infinity). A malicious or compromised HTTP/2 server can stream an endless sequence of CONTINUATION frames (each up to the peer-advertised SETTINGS_MAX_FRAME_SIZE) and drive the client's iolist to arbitrary size, causing memory exhaustion and BEAM process death. A single connection to an attacker-controlled HTTP/2 endpoint is sufficient. This issue affects mint: from 0.1.0 before 1.9.0.",
    "evidence": "osv:CVE-2026-49754",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-49754",
      "aliases": [
        "CVE-2026-49754",
        "EEF-CVE-2026-49754",
        "GHSA-2p26-p43x-fhp8"
      ],
      "metrics": [
        {
          "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"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/elixir-mint/mint",
              "type": "GIT",
              "events": [
                {
                  "introduced": "47889857fb36f07606ad9c2e52080d202d419058"
                },
                {
                  "fixed": "d1c8c5cafdfe5d3fdf1e42a2d0594d26855a12a1"
                },
                {
                  "fixed": "b662d127d3028b5426c88d4c9cc7fe430491a10b"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0.1.0"
                      },
                      {
                        "fixed": "1.9.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "fixed": "b662d127d3028b5426c88d4c9cc7fe430491a10b"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            },
            {
              "repo": "https://github.com/elixir-mint/mint.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "596ca4304504be68939c4929e0831557097962b8"
                },
                {
                  "fixed": "b662d127d3028b5426c88d4c9cc7fe430491a10b"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "596ca4304504be68939c4929e0831557097962b8"
                      },
                      {
                        "fixed": "b662d127d3028b5426c88d4c9cc7fe430491a10b"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  }
                ]
              }
            }
          ],
          "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",
            "v0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-49754.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:45.988829329Z",
      "provider": "osv",
      "references": [
        "https://cna.erlef.org/cves/CVE-2026-49754.html",
        "https://github.com",
        "https://osv.dev/vulnerability/EEF-CVE-2026-49754",
        "https://repo.hex.pm",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49754.json",
        "https://github.com/elixir-mint/mint/security/advisories/GHSA-2p26-p43x-fhp8",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-49754",
        "https://github.com/elixir-mint/mint/commit/b662d127d3028b5426c88d4c9cc7fe430491a10b",
        "https://github.com/elixir-mint/mint",
        "https://github.com/elixir-mint/mint.git"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-770"
        ],
        "cna_assigner": "EEF",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49754.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-49754",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 514218,
  "published_at": "2026-06-02T14:15:14.951+00:00"
}