{"id":"CVE-2026-5079","aliases":["CLSA-2026-1784077507","CLSA-2026-1786358483","EUVD-2026-36726","GHSA-72gw-mp4g-v24j","ROOT-APP-NPM-CVE-2026-5079"],"status":"published","title":"multer vulnerable to Denial of Service via deeply nested field names","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.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00279,"percentile":0.20468,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-400"],"published":"2026-06-15T13:56:45Z","modified":"2026-10-29T19:15:03Z","fixes":[{"ecosystem":"npm","package":"multer","fixed_in":["2.2.0","3.0.0-alpha.2"],"sources":["ghsa","osv"]},{"ecosystem":"TuxCare:npm","package":"multer","fixed_in":["1.4.5-lts.1-tuxcare.5"],"sources":["osv"]},{"ecosystem":"Root:npm","package":"multer","fixed_in":["1.4.4-lts.1-aikido.3","1.4.5-lts.2-aikido.9","1.4.4-lts.1-aikido.4","1.4.2-aikido.1","1.4.5-lts.1-aikido.2","1.4.5-lts.1-aikido.3","2.0.2-aikido.5","2.0.2-aikido.6","2.1.1-aikido.3","2.1.1-aikido.1","1.4.4-lts.1-aikido.1","1.4.4-aikido.4","1.4.5-lts.1-aikido.1","2.1.1-aikido.2","1.4.4-lts.1-aikido.2","1.4.4-aikido.5","1.4.5-lts.2-aikido.6","1.4.4-aikido.6","1.4.2-aikido.2","1.4.5-lts.2-aikido.7","1.4.5-lts.2-aikido.8","2.1.1-aikido.4","2.0.2-aikido.7","2.2.0-aikido.1","2.2.0-aikido.2"],"sources":["osv"]},{"ecosystem":"Root:npm","package":"@rootio/multer","fixed_in":["1.4.4-lts.1-root.io.3","1.4.5-lts.2-root.io.9","1.4.4-lts.1-root.io.4","1.4.2-root.io.1","1.4.5-lts.1-root.io.2","1.4.5-lts.1-root.io.3","2.0.2-root.io.5","2.0.2-root.io.6","2.1.1-root.io.3","2.1.1-root.io.1","1.4.4-lts.1-root.io.1","1.4.4-root.io.4","1.4.5-lts.1-root.io.1","2.1.1-root.io.2","1.4.4-lts.1-root.io.2","1.4.4-root.io.5","1.4.5-lts.2-root.io.6","1.4.4-root.io.6","1.4.2-root.io.2","1.4.5-lts.2-root.io.7","1.4.5-lts.2-root.io.8","2.1.1-root.io.4","2.0.2-root.io.7","2.2.0-root.io.1","2.2.0-root.io.2"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"multer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.0.0"},{"fixed":"2.2.0"}]}]},{"source":"ghsa","ecosystem":"npm","package":"multer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.0.0-alpha.1"},{"fixed":"3.0.0-alpha.2"}]}]},{"source":"osv","ecosystem":"TuxCare:npm","package":"multer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.4.5-lts.1-tuxcare.0"},{"fixed":"1.4.5-lts.1-tuxcare.5"}]}],"versions":["1.4.5-lts.1","1.4.5-lts.1-tuxcare.1","1.4.5-lts.1-tuxcare.2","1.4.5-lts.1-tuxcare.3","1.4.5-lts.1-tuxcare.4"]},{"source":"osv","ecosystem":"TuxCare:npm","package":"multer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.4.5-lts.2-tuxcare.0"},{"fixed":"1.4.5-lts.2-tuxcare.4"}]}],"versions":["1.4.5-lts.2","1.4.5-lts.2-tuxcare.1","1.4.5-lts.2-tuxcare.2","1.4.5-lts.2-tuxcare.3"],"bundled":2},{"source":"osv","ecosystem":"npm","package":"multer","ranges":[{"type":"SEMVER","events":[{"introduced":"1.0.0"},{"fixed":"2.2.0"}]}]},{"source":"osv","ecosystem":"npm","package":"multer","ranges":[{"type":"SEMVER","events":[{"introduced":"3.0.0-alpha.1"},{"fixed":"3.0.0-alpha.2"}]}]},{"source":"osv","ecosystem":"Root:npm","package":"multer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.4.4-lts.1-aikido.3"},{"fixed":"1.4.5-lts.2-aikido.9"},{"fixed":"1.4.4-lts.1-aikido.4"},{"fixed":"1.4.2-aikido.1"},{"fixed":"1.4.5-lts.1-aikido.2"},{"fixed":"1.4.5-lts.1-aikido.3"},{"fixed":"2.0.2-aikido.5"},{"fixed":"2.0.2-aikido.6"},{"fixed":"2.1.1-aikido.3"},{"fixed":"2.1.1-aikido.1"},{"fixed":"1.4.4-lts.1-aikido.1"},{"fixed":"1.4.4-aikido.4"},{"fixed":"1.4.5-lts.1-aikido.1"},{"fixed":"2.1.1-aikido.2"},{"fixed":"1.4.4-lts.1-aikido.2"},{"fixed":"1.4.4-aikido.5"},{"fixed":"1.4.5-lts.2-aikido.6"},{"fixed":"1.4.4-aikido.6"},{"fixed":"1.4.2-aikido.2"},{"fixed":"1.4.5-lts.2-aikido.7"},{"fixed":"1.4.5-lts.2-aikido.8"},{"fixed":"2.1.1-aikido.4"},{"fixed":"2.0.2-aikido.7"},{"fixed":"2.2.0-aikido.1"},{"fixed":"2.2.0-aikido.2"}]}]},{"source":"osv","ecosystem":"Root:npm","package":"@rootio/multer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.4.4-lts.1-root.io.3"},{"fixed":"1.4.5-lts.2-root.io.9"},{"fixed":"1.4.4-lts.1-root.io.4"},{"fixed":"1.4.2-root.io.1"},{"fixed":"1.4.5-lts.1-root.io.2"},{"fixed":"1.4.5-lts.1-root.io.3"},{"fixed":"2.0.2-root.io.5"},{"fixed":"2.0.2-root.io.6"},{"fixed":"2.1.1-root.io.3"},{"fixed":"2.1.1-root.io.1"},{"fixed":"1.4.4-lts.1-root.io.1"},{"fixed":"1.4.4-root.io.4"},{"fixed":"1.4.5-lts.1-root.io.1"},{"fixed":"2.1.1-root.io.2"},{"fixed":"1.4.4-lts.1-root.io.2"},{"fixed":"1.4.4-root.io.5"},{"fixed":"1.4.5-lts.2-root.io.6"},{"fixed":"1.4.4-root.io.6"},{"fixed":"1.4.2-root.io.2"},{"fixed":"1.4.5-lts.2-root.io.7"},{"fixed":"1.4.5-lts.2-root.io.8"},{"fixed":"2.1.1-root.io.4"},{"fixed":"2.0.2-root.io.7"},{"fixed":"2.2.0-root.io.1"},{"fixed":"2.2.0-root.io.2"}]}]}],"products":[{"vendor":"expressjs","product":"multer"},{"vendor":"multer","product":"multer"}],"references":[{"url":"https://github.com/expressjs/multer/security/advisories/GHSA-72gw-mp4g-v24j","tags":["Mitigation","Vendor Advisory","advisory","web"]},{"url":"https://cna.openjsf.org/security-advisories.html","tags":["Vendor Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-5079","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-72gw-mp4g-v24j"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/5xxx/CVE-2026-5079.json","tags":["advisory"]},{"url":"https://github.com/expressjs/multer","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-5079","title":"multer vulnerable to Denial of Service via deeply nested field names","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.","status":"published","published":"2026-06-15T13:56:45.52Z","modified":"2026-06-15T16:00:43.955Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T13:39:39.001586Z"}],"euvd":[{"id":"EUVD-2026-36726","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.","status":"published","published":"2026-06-15T13:56:45Z","modified":"2026-06-15T16:00:43Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T18:20:41.888684Z"}],"ghsa":[{"id":"GHSA-72gw-mp4g-v24j","title":"Multer vulnerable to Denial of Service via deeply nested field names","description":"### Impact\n\nMulter is vulnerable to a Denial of Service (DoS) via deeply nested field names in multipart form data. The `append-field` dependency parses bracket notation in field names (e.g., `a[b][c]`) 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\n### Patches\n\nUsers should upgrade to `2.2.0` and configure `limits.fieldNestingDepth` to the minimum depth their application requires.\n\n### Workarounds\n\nSet `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.","status":"published","published":"2026-06-17T18:12:27Z","modified":"2026-06-17T18:12:28Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:40:28.438722Z"}],"nvd":[{"id":"CVE-2026-5079","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.","status":"published","published":"2026-06-15T14:16:37.293Z","modified":"2026-06-17T10:58:24.257Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:12:23.846948Z"}],"osv":[{"id":"CVE-2026-5079","title":"multer vulnerable to Denial of Service via deeply nested field names","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.","status":"published","published":"2026-06-15T13:56:45.52Z","modified":"2026-10-28T02:30:33.054283765Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T15:45:07.431113Z"},{"id":"GHSA-72gw-mp4g-v24j","title":"Multer vulnerable to Denial of Service via deeply nested field names","description":"### Impact\n\nMulter is vulnerable to a Denial of Service (DoS) via deeply nested field names in multipart form data. The `append-field` dependency parses bracket notation in field names (e.g., `a[b][c]`) 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\n### Patches\n\nUsers should upgrade to `2.2.0` and configure `limits.fieldNestingDepth` to the minimum depth their application requires.\n\n### Workarounds\n\nSet `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.","status":"published","published":"2026-06-17T18:12:27Z","modified":"2026-06-17T18:26:29.243857Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T15:46:40.308826Z"},{"id":"CLSA-2026-1784077507","title":"TuxCare security update for multer (1 CVE)","description":"TuxCare rebuilt multer to address 1 CVE. Fixed in 1.4.5-lts.1-tuxcare.5.","status":"published","published":"2026-08-04T14:52:44Z","modified":"2026-10-15T09:47:36.236314971Z","updated_at":"2026-11-02T15:43:46.151924Z"},{"id":"CLSA-2026-1786358483","title":"TuxCare security update for multer (2 CVEs)","description":"TuxCare rebuilt multer to address 2 CVEs. Fixed in 1.4.5-lts.2-tuxcare.4.","status":"published","published":"2026-08-10T10:41:23Z","modified":"2026-10-15T09:45:59.745336293Z","updated_at":"2026-11-02T15:43:46.850893Z"},{"id":"ROOT-APP-NPM-CVE-2026-5079","title":"CVE-2026-5079 in multer - Patched by Root","description":"Root has patched CVE-2026-5079 in the multer package for Root:npm. Multiple fixed versions available.","status":"published","published":"2026-10-29T18:47:25Z","modified":"2026-10-29T19:15:03.18130247Z","updated_at":"2026-11-02T15:53:27.649662Z"}]}}