Vulnerability-Lookup

GHSA-RMMH-P597-PPVV

Vulnerability from github – Published: 2024-02-26 21:31 – Updated: 2026-04-24 20:36

Summary

Showdown vulnerable to Regular Expression Denial of Service (ReDoS) in link/anchor parsing

Details

Showdownjs, versions <= 2.1.0, anchors subparser used to parse links has a nested regular expression which can lead to denial of service conditions given malicious input.

Severity

5.3 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "showdown"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "2.1.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2024-1899"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-674",
      "CWE-777"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-24T20:36:01Z",
    "nvd_published_at": "2024-02-26T19:15:07Z",
    "severity": "MODERATE"
  },
  "details": "Showdownjs, versions \u003c= 2.1.0, `anchors` subparser used to parse links has a nested regular expression which can lead to denial of service conditions given malicious input.",
  "id": "GHSA-rmmh-p597-ppvv",
  "modified": "2026-04-24T20:36:01Z",
  "published": "2024-02-26T21:31:36Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-1899"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/showdownjs/showdown"
    },
    {
      "type": "WEB",
      "url": "https://www.tenable.com/security/research/tra-2024-05"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Showdown vulnerable to Regular Expression Denial of Service (ReDoS) in link/anchor parsing"
}

CVE-2024-1899 (GCVE-0-2024-1899)

Vulnerability from cvelistv5 – Published: 2024-02-26 18:45 – Updated: 2024-08-01 18:56

Title

Showdownjs Denial of Service

Summary

An issue in the anchors subparser of Showdownjs versions <= 2.1.0 could allow a remote attacker to cause denial of service conditions.

Severity

5.3 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2024-02-27 15:00 UTC

CWE

CWE-674 - Uncontrolled Recursion

Assigner

tenable mitre root Scorecard

References

1 reference

URL	Tags
https://www.tenable.com/security/research/tra-2024-05

Impacted products

2 products

Vendor	Product	Version
Showdownjs	Showdown	Affected: 0 , ≤ 2.1.0 (custom)
showdownjs	showdown	Affected: 0 , ≤ 2.1.0 (custom) cpe:2.3:a:showdownjs:showdown::::::::

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JSON

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{
  "containers": {
    "adp": [
      {
        "affected": [
          {
            "cpes": [
              "cpe:2.3:a:showdownjs:showdown:*:*:*:*:*:*:*:*"
            ],
            "defaultStatus": "unknown",
            "product": "showdown",
            "vendor": "showdownjs",
            "versions": [
              {
                "lessThanOrEqual": "2.1.0",
                "status": "affected",
                "version": "0",
                "versionType": "custom"
              }
            ]
          }
        ],
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2024-1899",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-02-27T15:00:09.096812Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-674",
                "description": "CWE-674 Uncontrolled Recursion",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2024-07-26T17:55:01.319Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      },
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-01T18:56:22.277Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://www.tenable.com/security/research/tra-2024-05"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Showdown",
          "repo": "https://github.com/showdownjs/showdown",
          "vendor": "Showdownjs",
          "versions": [
            {
              "lessThanOrEqual": "2.1.0",
              "status": "affected",
              "version": "0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003eAn issue in the anchors subparser of Showdownjs versions \u0026lt;= 2.1.0 could allow a remote attacker to cause denial of service conditions.\u003c/span\u003e\u003cbr\u003e"
            }
          ],
          "value": "An issue in the anchors subparser of Showdownjs versions \u003c= 2.1.0 could allow a remote attacker to cause denial of service conditions.\n"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2024-02-26T18:45:23.289Z",
        "orgId": "5ac1ecc2-367a-4d16-a0b2-35d495ddd0be",
        "shortName": "tenable"
      },
      "references": [
        {
          "url": "https://www.tenable.com/security/research/tra-2024-05"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "Showdownjs Denial of Service",
      "x_generator": {
        "engine": "Vulnogram 0.1.0-dev"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "5ac1ecc2-367a-4d16-a0b2-35d495ddd0be",
    "assignerShortName": "tenable",
    "cveId": "CVE-2024-1899",
    "datePublished": "2024-02-26T18:45:23.289Z",
    "dateReserved": "2024-02-26T18:20:18.142Z",
    "dateUpdated": "2024-08-01T18:56:22.277Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-RMMH-P597-PPVV

CVE-2024-1899 (GCVE-0-2024-1899)

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