Shescape: Quadratic-time denial of service in flag-protection

{
  "id": "f5f713c7cadf34453296879440926c408b07d9fe8a3830ebff21027b7209494e",
  "url": "https://osv.dev/vulnerability/CVE-2026-73413",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Shescape: Quadratic-time denial of service in flag-protection",
    "summary": "Shescape is a simple shell escape library for JavaScript. From 2.1.11 until 2.1.14 and 3.0.1, the flag-protection loop in compose in src/internal/compose.js repeatedly joins and slices flag fragments when flagProtection is enabled, which is the default, making processing quadratic in input size across the escape, escapeAll, quote, and quoteAll APIs. An attacker who can supply a large untrusted input containing many flag fragments can consume CPU and cause denial of service. This issue is fixed in versions 2.1.14 and 3.0.1.",
    "evidence": "osv:CVE-2026-73413",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-73413",
      "aliases": [
        "CVE-2026-73413",
        "GHSA-gm3r-q2wp-hw87"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/ericcornelissen/shescape",
              "type": "GIT",
              "events": [
                {
                  "introduced": "b1a0f675275a20c285aaea179e4e8e00b211ef1d"
                },
                {
                  "fixed": "ae0faa7bd31331aec3f21c623ee69a50e6663454"
                },
                {
                  "introduced": "68b9e590b7527fd9dbde91c450055059423942f6"
                },
                {
                  "fixed": "37303332910d456bf07bbf942c3ed98be156f365"
                },
                {
                  "fixed": "43d70b59d09bbe5c3fd02ef08b3a123e977ed9de"
                },
                {
                  "fixed": "b4b34c394e7f9da2775bb75381066b9a228c425f"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "2.1.11"
                      },
                      {
                        "fixed": "2.1.14"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "introduced": "3.0.0"
                      },
                      {
                        "fixed": "3.0.1"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "43d70b59d09bbe5c3fd02ef08b3a123e977ed9de"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "b4b34c394e7f9da2775bb75381066b9a228c425f"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "ae0faa7bd31331aec3f21c623ee69a50e6663454"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v2.1.14"
                  },
                  {
                    "range": [
                      {
                        "fixed": "37303332910d456bf07bbf942c3ed98be156f365"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v3.0.1"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v2.1.13",
            "v3.0.0",
            "v2.1.12",
            "v2.1.11"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-73413.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:25.679721919Z",
      "provider": "osv",
      "references": [
        "https://github.com/ericcornelissen/shescape/releases/tag/v2.1.14",
        "https://github.com/ericcornelissen/shescape/releases/tag/v3.0.1",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73413.json",
        "https://github.com/ericcornelissen/shescape/security/advisories/GHSA-gm3r-q2wp-hw87",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-73413",
        "https://github.com/ericcornelissen/shescape/commit/43d70b59d09bbe5c3fd02ef08b3a123e977ed9de",
        "https://github.com/ericcornelissen/shescape/commit/b4b34c394e7f9da2775bb75381066b9a228c425f",
        "https://github.com/ericcornelissen/shescape/pull/2649",
        "https://github.com/ericcornelissen/shescape/pull/2651"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-400",
          "CWE-407"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73413.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-73413",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 492513,
  "published_at": "2026-08-12T19:40:46.046+00:00"
}