{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:ninenines:cowlib:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0.6.0"
              },
              {
                "fixed": "2.16.1"
              }
            ],
            "source": [
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "a6626f3b4539b07366034b4953ab2df29e3a9d58"
            },
            {
              "fixed": "bae6b022af54566f3518a3aa59083b4591d552de"
            },
            {
              "fixed": "a4b8039ce8c93ab00867ef6b7e888822c09f4369"
            }
          ],
          "repo": "https://github.com/ninenines/cowlib",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "EEF",
    "cwe_ids": [
      "CWE-400"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/7xxx/CVE-2026-7790.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "8c0e428b012c59f553a264f285ed89d36f791e3e"
          },
          {
            "fixed": "a4b8039ce8c93ab00867ef6b7e888822c09f4369"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "Uncontrolled Resource Consumption vulnerability in ninenines cowlib (cow_http_te module) allows Excessive Allocation.\n\nThe chunked transfer-encoding parser in cow_http_te accepts an unbounded number of hex digits in the chunk-size field. Each digit causes a bignum multiplication (Len * 16 + digit), so parsing N hex digits requires O(N²) CPU work and O(N) memory. Additionally, when input is drip-fed, the parser discards the accumulated length on each partial read and restarts from zero on resumption, raising the cost to O(N³). An unauthenticated remote attacker can exploit this by sending an HTTP/1.1 request with Transfer-Encoding: chunked and a very long chunk-size hex string to cause denial of service through CPU exhaustion and memory amplification.\n\nThis vulnerability is associated with program file src/cow_http_te.erl and program routines cow_http_te:stream_chunked/2, cow_http_te:chunked_len/4.\n\nThis issue affects cowlib: from 0.6.0 before 2.16.1.",
  "id": "CVE-2026-7790",
  "modified": "2026-07-08T05:37:12.587665039Z",
  "published": "2026-05-11T18:06:41.490Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-7790"
    },
    {
      "type": "WEB",
      "url": "https://repo.hex.pm"
    },
    {
      "type": "ADVISORY",
      "url": "https://cna.erlef.org/cves/CVE-2026-7790.html"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/7xxx/CVE-2026-7790.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-7790"
    },
    {
      "type": "FIX",
      "url": "https://github.com/ninenines/cowlib/commit/a4b8039ce8c93ab00867ef6b7e888822c09f4369"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/ninenines/cowlib"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Unbounded chunk-size hex digits in cowlib cause quadratic CPU and memory DoS"
}