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BREW-TRAVIS-CVE-2023-27539 (GHSA-C6QG-CJJ8-47QP)

Vulnerability from osv_homebrew – Published: 2026-08-13 17:44 – Updated: 2026-08-13 17:44 – Source website
VLAI
Summary
Possible Denial of Service Vulnerability in Rack's header parsing
Details

There is a denial of service vulnerability in the header parsing component of Rack. This vulnerability has been assigned the CVE identifier CVE-2023-27539.

Versions Affected: >= 2.0.0 Not affected: None. Fixed Versions: 2.2.6.4, 3.0.6.1

Impact

Carefully crafted input can cause header parsing in Rack to take an unexpected amount of time, possibly resulting in a denial of service attack vector. Any applications that parse headers using Rack (virtually all Rails applications) are impacted.

Workarounds

Setting Regexp.timeout in Ruby 3.2 is a possible workaround.

References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "resource": "rack",
        "resource_purl": "pkg:gem/rack@3.0.11",
        "upstream_fixed_in": "3.0.6.1"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "travis",
        "purl": "pkg:brew/travis"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.14.0_2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "RubyGems",
        "key": "pkg:gem/rack@3.0.11",
        "name": "rack",
        "resource": "rack",
        "strategy": "registry",
        "subject_version": "3.0.11"
      }
    ]
  },
  "details": "There is a denial of service vulnerability in the header parsing component of Rack. This vulnerability has been assigned the CVE identifier CVE-2023-27539.\n\nVersions Affected: \u003e= 2.0.0 Not affected: None. Fixed Versions: 2.2.6.4, 3.0.6.1\n\n# Impact\nCarefully crafted input can cause header parsing in Rack to take an unexpected amount of time, possibly resulting in a denial of service attack vector. Any applications that parse headers using Rack (virtually all Rails applications) are impacted.\n\n# Workarounds\nSetting Regexp.timeout in Ruby 3.2 is a possible workaround.\n",
  "id": "BREW-travis-CVE-2023-27539",
  "modified": "2026-08-13T17:44:53Z",
  "published": "2026-08-13T17:44:53Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-27539"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rack/rack/commit/231ef369ad0b542575fb36c74fcfcfabcf6c530c"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rack/rack/commit/ee7919ea04303717858be1c3f16b406adc6d8cff"
    },
    {
      "type": "WEB",
      "url": "https://discuss.rubyonrails.org/t/cve-2023-27539-possible-denial-of-service-vulnerability-in-racks-header-parsing/82466"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/rack/rack"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2023-27539.yml"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2023/04/msg00017.html"
    },
    {
      "type": "WEB",
      "url": "https://security.netapp.com/advisory/ntap-20231208-0016"
    },
    {
      "type": "WEB",
      "url": "https://www.debian.org/security/2023/dsa-5530"
    }
  ],
  "schema_version": "1.7.3",
  "summary": "Possible Denial of Service Vulnerability in Rack\u0027s header parsing",
  "upstream": [
    "GHSA-c6qg-cjj8-47qp",
    "CVE-2023-27539"
  ]
}



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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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