Security advisory

{
  "id": "378f29c9cfd75b9b16e78827ba12fe8b8b2afb3c9cb22f9924032f74958fa3e6",
  "url": "https://osv.dev/vulnerability/CVE-2024-21503",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2024-21503",
    "summary": "Versions of the package black before 24.3.0 are vulnerable to Regular Expression Denial of Service (ReDoS) via the lines_with_leading_tabs_expanded function in the strings.py file. An attacker could exploit this vulnerability by crafting a malicious input that causes a denial of service. Exploiting this vulnerability is possible when running Black on untrusted input, or if you habitually put thousands of leading tab characters in your docstrings.",
    "evidence": "osv:CVE-2024-21503",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2024-21503",
      "aliases": [
        "CVE-2024-21503",
        "GHSA-fj7x-q9j7-g6q6",
        "PYSEC-2024-48"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/psf/black",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "552baf822992936134cbd31a38f69c8cfe7c0f05"
                },
                {
                  "fixed": "f00093672628d212b8965a8993cee8bedf5fe9b8"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "24.3.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "fixed": "552baf822992936134cbd31a38f69c8cfe7c0f05"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "24.3.0"
                  },
                  {
                    "range": [
                      {
                        "fixed": "f00093672628d212b8965a8993cee8bedf5fe9b8"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "24.2.0",
            "24.1.1",
            "24.1.0",
            "23.12.1",
            "23.12.0",
            "23.11.0",
            "23.10.1",
            "23.10.0",
            "23.9.1",
            "23.9.0",
            "23.7.0",
            "23.3.0",
            "23.1.0",
            "22.12.0",
            "22.10.0",
            "22.8.0",
            "22.6.0",
            "22.3.0",
            "22.1.0",
            "21.12b0",
            "21.11b1",
            "21.11b0",
            "21.10b0",
            "21.9b0",
            "21.8b0",
            "21.7b0",
            "21.6b0",
            "21.5b2",
            "21.5b1",
            "21.5b0",
            "21.4b2",
            "21.4b1",
            "21.4b0",
            "20.8b1",
            "20.8b0",
            "19.10b0",
            "19.3b0",
            "18.9b0",
            "18.6b4",
            "18.6b3",
            "18.6b2",
            "18.6b1",
            "18.6b0",
            "18.5b1",
            "18.5b0",
            "18.4a4",
            "18.4a3",
            "18.4a2",
            "18.4a1",
            "18.4a0",
            "18.3a4",
            "18.3a3",
            "18.3a2",
            "18.3a1",
            "18.3a0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-21503.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:27.173756582Z",
      "provider": "osv",
      "references": [
        "https://github.com/psf/black/releases/tag/24.3.0",
        "https://security.snyk.io/vuln/SNYK-PYTHON-BLACK-6256273",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/21xxx/CVE-2024-21503.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2024-21503",
        "https://github.com/psf/black/commit/f00093672628d212b8965a8993cee8bedf5fe9b8"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-1333"
        ],
        "cna_assigner": "snyk",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/21xxx/CVE-2024-21503.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2024-21503",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 493776,
  "published_at": "2024-03-19T05:00:01.474+00:00"
}