{"api_version":"1","generated_at":"2026-04-16T21:03:47+00:00","cve":"CVE-2026-4923","urls":{"html":"https://cve.report/CVE-2026-4923","api":"https://cve.report/api/cve/CVE-2026-4923.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-4923","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-4923"},"summary":{"title":"path-to-regexp vulnerable to Regular Expression Denial of Service via multiple wildcards","description":"Impact:\n\nWhen using multiple wildcards, combined with at least one parameter, a regular expression can be generated that is vulnerable to ReDoS. This backtracking vulnerability requires the second wildcard to be somewhere other than the end of the path.\n\nUnsafe examples:\n\n/*foo-*bar-:baz\n/*a-:b-*c-:d\n/x/*a-:b/*c/y\n\nSafe examples:\n\n/*foo-:bar\n/*foo-:bar-*baz\n\nPatches:\n\nUpgrade to version 8.4.0.\n\nWorkarounds:\n\nIf you are using multiple wildcard parameters, you can check the regex output with a tool such as https://makenowjust-labs.github.io/recheck/playground/ to confirm whether a path is vulnerable.","state":"PUBLISHED","assigner":"openjs","published_at":"2026-03-26 19:17:08","updated_at":"2026-04-16 18:03:37"},"problem_types":["CWE-1333","CWE-1333 CWE-1333: Inefficient Regular Expression Complexity"],"metrics":[{"version":"3.1","source":"ce714d77-add3-4f53-aff5-83d477b104bb","type":"Secondary","score":"5.9","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":5.9,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"CVSS","score":"5.9","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"baseScore":5.9,"baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"references":[{"url":"https://cna.openjsf.org/security-advisories.html","name":"https://cna.openjsf.org/security-advisories.html","refsource":"ce714d77-add3-4f53-aff5-83d477b104bb","tags":["Third Party Advisory"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-4923","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-4923","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"path-to-regexp","product":"path-to-regexp","version":"affected 8.0.0 8.4.0 semver","platforms":[]},{"source":"CNA","vendor":"path-to-regexp","product":"path-to-regexp","version":"unaffected 8.4.0 semver","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[{"source":"CNA","value":"blakeembrey","lang":"en"},{"source":"CNA","value":"UlisesGascon","lang":"en"}],"nvd_cpes":[{"cve_year":"2026","cve_id":"4923","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"pillarjs","cpe5":"path-to-regexp","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"node.js","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"4923","cve":"CVE-2026-4923","epss":"0.000520000","percentile":"0.165520000","score_date":"2026-04-05","updated_at":"2026-04-06 00:05:32"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2026-4923","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-03-27T13:46:47.360477Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-03-27T13:58:03.925Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"defaultStatus":"unaffected","packageURL":"pkg:npm/path-to-regexp","product":"path-to-regexp","vendor":"path-to-regexp","versions":[{"lessThan":"8.4.0","status":"affected","version":"8.0.0","versionType":"semver"},{"status":"unaffected","version":"8.4.0","versionType":"semver"}]}],"credits":[{"lang":"en","type":"remediation developer","value":"blakeembrey"},{"lang":"en","type":"remediation reviewer","value":"UlisesGascon"}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"Impact:\n\nWhen using multiple wildcards, combined with at least one parameter, a regular expression can be generated that is vulnerable to ReDoS. This backtracking vulnerability requires the second wildcard to be somewhere other than the end of the path.\n\nUnsafe examples:\n\n/*foo-*bar-:baz\n/*a-:b-*c-:d\n/x/*a-:b/*c/y\n\nSafe examples:\n\n/*foo-:bar\n/*foo-:bar-*baz\n\nPatches:\n\nUpgrade to version 8.4.0.\n\nWorkarounds:\n\nIf you are using multiple wildcard parameters, you can check the regex output with a tool such as https://makenowjust-labs.github.io/recheck/playground/ to confirm whether a path is vulnerable."}],"value":"Impact:\n\nWhen using multiple wildcards, combined with at least one parameter, a regular expression can be generated that is vulnerable to ReDoS. This backtracking vulnerability requires the second wildcard to be somewhere other than the end of the path.\n\nUnsafe examples:\n\n/*foo-*bar-:baz\n/*a-:b-*c-:d\n/x/*a-:b/*c/y\n\nSafe examples:\n\n/*foo-:bar\n/*foo-:bar-*baz\n\nPatches:\n\nUpgrade to version 8.4.0.\n\nWorkarounds:\n\nIf you are using multiple wildcard parameters, you can check the regex output with a tool such as https://makenowjust-labs.github.io/recheck/playground/ to confirm whether a path is vulnerable."}],"metrics":[{"cvssV3_1":{"baseScore":5.9,"baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-1333","description":"CWE-1333: Inefficient Regular Expression Complexity","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-03-26T19:02:00.729Z","orgId":"ce714d77-add3-4f53-aff5-83d477b104bb","shortName":"openjs"},"references":[{"url":"https://cna.openjsf.org/security-advisories.html"}],"title":"path-to-regexp vulnerable to Regular Expression Denial of Service via multiple wildcards","x_generator":{"engine":"cve-kit 1.0.0"}}},"cveMetadata":{"assignerOrgId":"ce714d77-add3-4f53-aff5-83d477b104bb","assignerShortName":"openjs","cveId":"CVE-2026-4923","datePublished":"2026-03-26T19:02:00.729Z","dateReserved":"2026-03-26T18:05:44.717Z","dateUpdated":"2026-03-27T13:58:03.925Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-03-26 19:17:08","lastModifiedDate":"2026-04-16 18:03:37","problem_types":["CWE-1333","CWE-1333 CWE-1333: Inefficient Regular Expression Complexity"],"metrics":{"cvssMetricV31":[{"source":"ce714d77-add3-4f53-aff5-83d477b104bb","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":5.9,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":2.2,"impactScore":3.6}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:pillarjs:path-to-regexp:*:*:*:*:*:node.js:*:*","versionStartIncluding":"8.0.0","versionEndExcluding":"8.4.0","matchCriteriaId":"DB421812-F7E3-4CC5-B02B-53CCBFDFB671"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"4923","Ordinal":"1","Title":"path-to-regexp vulnerable to Regular Expression Denial of Servic","CVE":"CVE-2026-4923","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"4923","Ordinal":"1","NoteData":"Impact:\n\nWhen using multiple wildcards, combined with at least one parameter, a regular expression can be generated that is vulnerable to ReDoS. This backtracking vulnerability requires the second wildcard to be somewhere other than the end of the path.\n\nUnsafe examples:\n\n/*foo-*bar-:baz\n/*a-:b-*c-:d\n/x/*a-:b/*c/y\n\nSafe examples:\n\n/*foo-:bar\n/*foo-:bar-*baz\n\nPatches:\n\nUpgrade to version 8.4.0.\n\nWorkarounds:\n\nIf you are using multiple wildcard parameters, you can check the regex output with a tool such as https://makenowjust-labs.github.io/recheck/playground/ to confirm whether a path is vulnerable.","Type":"Description","Title":"path-to-regexp vulnerable to Regular Expression Denial of Servic"}]}}}