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BREW-PGSLICE-CVE-2025-27220 (GHSA-MHWM-JH88-3GJF)

Vulnerability from osv_homebrew – Published: 2026-08-13 17:26 – Updated: 2026-08-13 17:26 – Source website
VLAI
Summary
CGI has Regular Expression Denial of Service (ReDoS) potential in Util#escapeElement
Details

There is a possibility for Regular expression Denial of Service (ReDoS) by in the cgi gem. This vulnerability has been assigned the CVE identifier CVE-2025-27220. We recommend upgrading the cgi gem.

Details

The regular expression used in CGI::Util#escapeElement is vulnerable to ReDoS. The crafted input could lead to a high CPU consumption.

This vulnerability only affects Ruby 3.1 and 3.2. If you are using these versions, please update CGI gem to version 0.3.5.1, 0.3.7, 0.4.2 or later.

Affected versions

cgi gem versions <= 0.3.5, 0.3.6, 0.4.0 and 0.4.1.

Credits

Thanks to svalkanov for discovering this issue. Also thanks to nobu for fixing this vulnerability.

Severity
4.0 (Medium)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:L
6.3 (Medium)
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "resource": "cgi",
        "resource_purl": "pkg:gem/cgi@0.5.1",
        "upstream_fixed_in": "0.4.2"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "pgslice",
        "purl": "pkg:brew/pgslice"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.7.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "registry",
    "upstream_evidence": [
      {
        "ecosystem": "RubyGems",
        "key": "pkg:gem/cgi@0.5.1",
        "name": "cgi",
        "resource": "cgi",
        "strategy": "registry",
        "subject_version": "0.5.1"
      }
    ]
  },
  "details": "There is a possibility for Regular expression Denial of Service (ReDoS) by in the cgi gem. This vulnerability has been assigned the CVE identifier CVE-2025-27220. We recommend upgrading the cgi gem.\n\n## Details\n\nThe regular expression used in `CGI::Util#escapeElement` is vulnerable to ReDoS. The crafted input could lead to a high CPU consumption.\n\nThis vulnerability only affects Ruby 3.1 and 3.2. If you are using these versions, please update CGI gem to version 0.3.5.1, 0.3.7, 0.4.2 or later.\n\n## Affected versions\n\ncgi gem versions \u003c= 0.3.5, 0.3.6, 0.4.0 and 0.4.1.\n\n## Credits\n\nThanks to svalkanov for discovering this issue.\nAlso thanks to nobu for fixing this vulnerability.",
  "id": "BREW-pgslice-CVE-2025-27220",
  "modified": "2026-08-13T17:26:07Z",
  "published": "2026-08-13T17:26:07Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-27220"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ruby/cgi/pull/52"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ruby/cgi/pull/53"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ruby/cgi/pull/54"
    },
    {
      "type": "WEB",
      "url": "https://hackerone.com/reports/2890322"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/ruby/cgi"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/cgi/CVE-2025-27220.yml"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00008.html"
    },
    {
      "type": "WEB",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-27220"
    },
    {
      "type": "WEB",
      "url": "https://www.ruby-lang.org/en/news/2025/02/26/security-advisories"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "CGI has Regular Expression Denial of Service (ReDoS) potential in Util#escapeElement",
  "upstream": [
    "GHSA-mhwm-jh88-3gjf",
    "CVE-2025-27220"
  ]
}



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