{"cve":{"cve_id":"CVE-2026-5079","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.00278,"epss_percentile":0.19413,"epss_as_of":"2026-06-23","description":"Impact: multer versions 1.0.0 through 2.1.1 and 3.0.0-alpha.1 are vulnerable to a Denial of Service via deeply nested field names in multipart form data. The append-field dependency parses bracket notation in field names with no limit on nesting depth, allowing an attacker to force allocation of deeply nested object structures that consume CPU and memory. A single HTTP request with a crafted multipart body is sufficient to exploit this.\n\nPatches: Users should upgrade to multer 2.2.0 (2.x line) or 3.0.0-alpha.2 (3.x prerelease) and configure the new limits.fieldNestingDepth option to the minimum depth their application requires.\n\nWorkarounds: Set limits.fields to a reasonable value to reduce the number of fields an attacker can send per request. This does not fully mitigate the issue but limits the impact.","published_at":"2026-06-15T13:56:45.520000Z","last_modified_at":null,"cvss_v3_score":7.5,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvss_v3_severity":"HIGH","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-400"],"nvd_references":["https://github.com/expressjs/multer/security/advisories/GHSA-72gw-mp4g-v24j","https://cna.openjsf.org/security-advisories.html"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:39.878444Z","updated_at":"2026-06-28T23:30:47.822556Z"},"effective_severity":"HIGH","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"N","value_label":"None"},{"metric":"I","name":"Integrity","value":"N","value_label":"None"},{"metric":"A","name":"Availability","value":"H","value_label":"High"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"multer","vendor_name":"multer","product_slug":"multer","product_name":"multer","version_start":"1.0.0","version_start_inclusive":true,"version_end":"2.2.0","version_end_inclusive":false,"cpe23_uri":"cve5:multer:multer:1.0.0:2.2.0"},{"vendor_slug":"multer","vendor_name":"multer","product_slug":"multer","product_name":"multer","version_start":"2.2.0","version_start_inclusive":true,"version_end":"2.2.0","version_end_inclusive":true,"cpe23_uri":"cve5:multer:multer:2.2.0:2.2.0"},{"vendor_slug":"multer","vendor_name":"multer","product_slug":"multer","product_name":"multer","version_start":"3.0.0-alpha.1","version_start_inclusive":true,"version_end":"3.0.0-alpha.2","version_end_inclusive":false,"cpe23_uri":"cve5:multer:multer:3.0.0-alpha.1:3.0.0-alpha.2"},{"vendor_slug":"multer","vendor_name":"multer","product_slug":"multer","product_name":"multer","version_start":"3.0.0-alpha.2","version_start_inclusive":true,"version_end":"3.0.0-alpha.2","version_end_inclusive":true,"cpe23_uri":"cve5:multer:multer:3.0.0-alpha.2:3.0.0-alpha.2"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/expressjs/multer/security/advisories/GHSA-72gw-mp4g-v24j","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://cna.openjsf.org/security-advisories.html","source_type":"VENDOR_ADVISORY","tags":["advisory"]}],"timeline":[{"type":"published","at":"2026-06-15T13:56:45.520000Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:55:42.709123Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:55:42.709123Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:55:42.709123Z","label":"CVSS score revised","source":"cvelistv5"}]}