react/http: A malformed HTTP chunked body can lead to a denial-of-service and peg the CPU

{
  "id": "bf32c964a45c3f17d3bbfc7e4780fdd697215837f22da219f336105044390067",
  "url": "https://osv.dev/vulnerability/CVE-2026-84997",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "react/http: A malformed HTTP chunked body can lead to a denial-of-service and peg the CPU",
    "summary": "react/http is an event-driven, streaming HTTP client and server implementation for ReactPHP. From 0.6.0 until 1.11.1, React\\Http\\Io\\ChunkedDecoder could enter an infinite loop while processing a malformed Transfer-Encoding: chunked body because handleData required its buffer to shrink on every iteration. An incomplete terminal-chunk trailer without CRLF left the buffer unchanged after strpos returned false, and exactly two non-CRLF bytes after a completed non-terminal chunk bypassed both the error and wait guards. The affected decoder processes request bodies for React\\Http\\HttpServer and response bodies for React\\Http\\Browser, allowing a malicious client to freeze a server or a malicious or compromised server to freeze a client. A reverse proxy that normalizes inbound requests may protect the server direction but does not protect outbound Browser requests. This issue is fixed in version 1.11.1.",
    "evidence": "osv:CVE-2026-84997",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-84997",
      "aliases": [
        "CVE-2026-84997",
        "GHSA-x424-64qh-5j54"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/reactphp/http",
              "type": "GIT",
              "events": [
                {
                  "introduced": "b5e7d9bfc9effe8ec723af942c66df042ad17fe6"
                },
                {
                  "fixed": "e5b8eb2654dec6cbbc692a39f05ea4ecd40c8cc1"
                },
                {
                  "fixed": "b6d4688790adf3797071fcf88a3fc4225f30486a"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0.6.0"
                      },
                      {
                        "fixed": "1.11.1"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "b6d4688790adf3797071fcf88a3fc4225f30486a"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "e5b8eb2654dec6cbbc692a39f05ea4ecd40c8cc1"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v1.11.1"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.11.0",
            "v1.10.0",
            "v1.9.0",
            "v1.8.0",
            "v1.7.0",
            "v1.6.0",
            "v1.5.0",
            "v1.4.0",
            "v1.3.0",
            "v1.2.0",
            "v1.1.0",
            "v1.0.0",
            "v0.8.7",
            "v0.8.6",
            "v0.8.5",
            "v0.8.4",
            "v0.8.3",
            "v0.8.2",
            "v0.8.1",
            "v0.8.0",
            "v0.7.4",
            "v0.7.3",
            "v0.7.2",
            "v0.7.1",
            "v0.7.0",
            "v0.6.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84997.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:42.097609779Z",
      "provider": "osv",
      "references": [
        "https://github.com/reactphp/http/releases/tag/v1.11.1",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84997.json",
        "https://github.com/reactphp/http/security/advisories/GHSA-x424-64qh-5j54",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-84997",
        "https://github.com/reactphp/http/commit/b6d4688790adf3797071fcf88a3fc4225f30486a"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-835"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84997.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-84997",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 510018,
  "published_at": "2026-09-16T14:07:52.948+00:00"
}