CVE-2026-115701

Full vulnerability record from the local CVENow database.

Description

Allocation of Resources Without Limits or Throttling vulnerability in ninenines cowboy allows an unauthenticated remote attacker to exhaust connection process memory over HTTP/1.1. Once a request has been received in full and its handler is still running, cowboy_http:parse/2 in src/cowboy_http.erl appends every further byte that arrives on the keep-alive connection to the connection buffer and returns to the receive loop without parsing it. The socket stays in active mode and no limit applies to this buffer: max_request_line_length, max_headers and the other parser limits only take effect once the handler returns and parsing resumes, and the only timer in this state is idle_timeout (default 60 seconds), which is reset on every received chunk. A client can therefore send an arbitrary amount of data on one connection for as long as the handler runs, and a few connections to an endpoint that holds requests open can drive the Erlang VM into out-of-memory conditions. This issue affects cowboy: from 2.18.0 onward.

Severity

HIGH

CVSS score

8.2 (v4.0)

Vulnerability status

Received

Source identifier

6b3ad84c-e1a6-4bf7-a703-f496b71e49db

Published

2026-11-06 11:17:05.223000

Last modified

2026-11-06 11:17:05.223000

View original CVE JSON

{
  "id": "CVE-2026-115701",
  "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
  "published": "2026-11-06T11:17:05.223",
  "lastModified": "2026-11-06T11:17:05.223",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Allocation of Resources Without Limits or Throttling vulnerability in ninenines cowboy allows an unauthenticated remote attacker to exhaust connection process memory over HTTP/1.1.\n\nOnce a request has been received in full and its handler is still running, cowboy_http:parse/2 in src/cowboy_http.erl appends every further byte that arrives on the keep-alive connection to the connection buffer and returns to the receive loop without parsing it. The socket stays in active mode and no limit applies to this buffer: max_request_line_length, max_headers and the other parser limits only take effect once the handler returns and parsing resumes, and the only timer in this state is idle_timeout (default 60 seconds), which is reset on every received chunk. A client can therefore send an arbitrary amount of data on one connection for as long as the handler runs, and a few connections to an endpoint that holds requests open can drive the Erlang VM into out-of-memory conditions.\n\nThis issue affects cowboy: from 2.18.0 onward."
    }
  ],
  "affected": [
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "affectedData": [
        {
          "vendor": "ninenines",
          "product": "cowboy",
          "defaultStatus": "unaffected",
          "collectionURL": "https://repo.hex.pm",
          "packageName": "cowboy",
          "cpes": [
            "cpe:2.3:a:ninenines:cowboy:*:*:*:*:*:*:*:*"
          ],
          "modules": [
            "cowboy_http"
          ],
          "programFiles": [
            "src/cowboy_http.erl"
          ],
          "programRoutines": [
            {
              "name": "cowboy_http:parse/2"
            },
            {
              "name": "cowboy_http:loop/1"
            }
          ],
          "repo": "https://github.com/ninenines/cowboy",
          "packageURL": "pkg:hex/cowboy",
          "versions": [
            {
              "version": "2.18.0",
              "lessThan": "*",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "ninenines",
          "product": "cowboy",
          "defaultStatus": "unaffected",
          "collectionURL": "https://github.com",
          "packageName": "ninenines/cowboy",
          "cpes": [
            "cpe:2.3:a:ninenines:cowboy:*:*:*:*:*:*:*:*"
          ],
          "modules": [
            "cowboy_http"
          ],
          "programFiles": [
            "src/cowboy_http.erl"
          ],
          "programRoutines": [
            {
              "name": "cowboy_http:parse/2"
            },
            {
              "name": "cowboy_http:loop/1"
            }
          ],
          "repo": "https://github.com/ninenines/cowboy",
          "packageURL": "pkg:github/ninenines/cowboy",
          "versions": [
            {
              "version": "faf5594fbf74530ace90b0c46c936bdc2cf82081",
              "lessThan": "3a630c07e1521abf63a1b9ea080509aa1337b60d",
              "versionType": "git",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "baseScore": 8.2,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnAvailabilityImpact": "HIGH",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-770"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://cna.erlef.org/cves/CVE-2026-115701.html",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://github.com/ninenines/cowboy/commit/3a630c07e1521abf63a1b9ea080509aa1337b60d",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://github.com/ninenines/cowboy/commit/faf5594fbf74530ace90b0c46c936bdc2cf82081",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-115701",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    }
  ]
}