{"id":"CVE-2026-77078","aliases":["CLSA-2026-1788988502","CLSA-2026-1790176219","CLSA-2026-1790604779","DEBIAN-CVE-2026-77078","EUVD-2026-67930","GHSA-wc9g-mqfw-jrwm","ROOT-APP-NPM-CVE-2026-77078"],"status":"published","title":"multer vulnerable to Denial of Service via crafted multipart field names","description":"multer is a middleware for handling multipart/form-data in Node.js. A small multipart request containing two specially crafted text field names can cause an uncaught RangeError (Invalid array length) that terminates the Node.js process. The first field uses a very large numeric array index to allocate a maximum-length sparse array, and a second field then pushes past that length, which throws inside the append-field dependency and is not caught by multer. All versions before 2.3.0 are affected, and the issue is a remotely triggerable denial of service. The issue is fixed in multer 2.3.0. Upgrade to multer 2.3.0 to remediate.","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":0.00488,"percentile":0.42288,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":true,"fix_available":true},"cwes":["CWE-248"],"published":"2026-08-28T20:03:23Z","modified":"2026-11-04T09:15:05Z","exploits":[{"source":"pocgithub","id":"wtfkimi/CVE-2026-77078","title":"wtfkimi/CVE-2026-77078","date":"2026-09-21","url":"https://github.com/wtfkimi/CVE-2026-77078"}],"fixes":[{"ecosystem":"npm","package":"multer","fixed_in":["2.3.0"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:14","package":"node-multer","fixed_in":["2.4.0+~cs3.2.0-1"],"sources":["osv"]},{"ecosystem":"Root:npm","package":"multer","fixed_in":["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.6","2.1.1-aikido.3","2.2.0-aikido.1","1.4.4-aikido.5","1.4.4-aikido.6","1.4.2-aikido.2","2.1.1-aikido.4","2.0.2-aikido.7","2.2.0-aikido.2","2.3.0-aikido.2","2.3.0-aikido.1"],"sources":["osv"]},{"ecosystem":"Root:npm","package":"@rootio/multer","fixed_in":["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.6","2.1.1-root.io.3","2.2.0-root.io.1","1.4.4-root.io.5","1.4.4-root.io.6","1.4.2-root.io.2","2.1.1-root.io.4","2.0.2-root.io.7","2.2.0-root.io.2","2.3.0-root.io.2","2.3.0-root.io.1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"multer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.3.0"}]}]},{"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.5"}]}],"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","1.4.5-lts.2-tuxcare.4"],"bundled":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.9"}]}],"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","1.4.5-lts.1-tuxcare.5","1.4.5-lts.1-tuxcare.6","1.4.5-lts.1-tuxcare.7","1.4.5-lts.1-tuxcare.8"],"bundled":2},{"source":"osv","ecosystem":"TuxCare:npm","package":"multer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.2.0-tuxcare.0"},{"fixed":"2.2.0-tuxcare.1"}]}],"versions":["2.2.0"],"bundled":2},{"source":"osv","ecosystem":"Debian:14","package":"node-multer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.4.0+~cs3.2.0-1"}]}],"versions":["2.2.0+~cs3.1.0-1","2.2.0+~cs3.1.0-2","2.2.0+~cs3.2.0-1"]},{"source":"osv","ecosystem":"npm","package":"multer","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2.3.0"}]}]},{"source":"osv","ecosystem":"Root:npm","package":"multer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"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.6"},{"fixed":"2.1.1-aikido.3"},{"fixed":"2.2.0-aikido.1"},{"fixed":"1.4.4-aikido.5"},{"fixed":"1.4.4-aikido.6"},{"fixed":"1.4.2-aikido.2"},{"fixed":"2.1.1-aikido.4"},{"fixed":"2.0.2-aikido.7"},{"fixed":"2.2.0-aikido.2"},{"fixed":"2.3.0-aikido.2"},{"fixed":"2.3.0-aikido.1"}]}]},{"source":"osv","ecosystem":"Root:npm","package":"@rootio/multer","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"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.6"},{"fixed":"2.1.1-root.io.3"},{"fixed":"2.2.0-root.io.1"},{"fixed":"1.4.4-root.io.5"},{"fixed":"1.4.4-root.io.6"},{"fixed":"1.4.2-root.io.2"},{"fixed":"2.1.1-root.io.4"},{"fixed":"2.0.2-root.io.7"},{"fixed":"2.2.0-root.io.2"},{"fixed":"2.3.0-root.io.2"},{"fixed":"2.3.0-root.io.1"}]}]}],"products":[{"vendor":"expressjs","product":"multer"},{"vendor":"multer","product":"multer"}],"references":[{"url":"https://github.com/expressjs/multer/security/advisories/GHSA-wc9g-mqfw-jrwm","tags":["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-2026-77078","tags":["advisory"]},{"url":"https://github.com/expressjs/multer/commit/87a584e8c8d4da873292635fa1d8c4d78d985b76","tags":["web"]},{"url":"https://github.com/expressjs/multer/releases/tag/v2.3.0","tags":["web"]},{"url":"https://github.com/advisories/GHSA-wc9g-mqfw-jrwm"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77078.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-77078","tags":["advisory"]},{"url":"https://github.com/expressjs/multer","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-77078","title":"multer vulnerable to Denial of Service via crafted multipart field names","description":"multer is a middleware for handling multipart/form-data in Node.js. A small multipart request containing two specially crafted text field names can cause an uncaught RangeError (Invalid array length) that terminates the Node.js process. The first field uses a very large numeric array index to allocate a maximum-length sparse array, and a second field then pushes past that length, which throws inside the append-field dependency and is not caught by multer. All versions before 2.3.0 are affected, and the issue is a remotely triggerable denial of service. The issue is fixed in multer 2.3.0. Upgrade to multer 2.3.0 to remediate.","status":"published","published":"2026-08-28T20:03:23.114Z","modified":"2026-08-31T18:40:24.545Z","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-248"],"updated_at":"2026-11-02T14:20:15.712761Z"}],"euvd":[{"id":"EUVD-2026-67930","description":"multer is a middleware for handling multipart/form-data in Node.js. A small multipart request containing two specially crafted text field names can cause an uncaught RangeError (Invalid array length) that terminates the Node.js process. The first field uses a very large numeric array index to allocate a maximum-length sparse array, and a second field then pushes past that length, which throws inside the append-field dependency and is not caught by multer. All versions before 2.3.0 are affected, and the issue is a remotely triggerable denial of service. The issue is fixed in multer 2.3.0. Upgrade to multer 2.3.0 to remediate.","status":"published","published":"2026-08-28T20:03:23Z","modified":"2026-08-31T18:40:24Z","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":"2026-11-02T18:01:20.215322Z"}],"ghsa":[{"id":"GHSA-wc9g-mqfw-jrwm","title":"multer vulnerable to Denial of Service via crafted multipart field names","description":"### Impact\n\nA vulnerability in multer allows a remote, unauthenticated attacker to crash the Node.js process with a single `multipart/form-data` request. Two specially crafted text field names cause an uncaught `RangeError: Invalid array length` inside multer's field parsing, which is not routed to the application error handler and terminates the process. All applications using multer to parse multipart requests are affected.\n\n### Patches\n\nUsers should upgrade to `2.3.0`.\n\n### Workarounds\n\nNone.","status":"published","published":"2026-09-08T21:30:20Z","modified":"2026-09-08T21:30:22Z","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-248"],"updated_at":"2026-11-02T14:41:14.764963Z"}],"nvd":[{"id":"CVE-2026-77078","description":"multer is a middleware for handling multipart/form-data in Node.js. A small multipart request containing two specially crafted text field names can cause an uncaught RangeError (Invalid array length) that terminates the Node.js process. The first field uses a very large numeric array index to allocate a maximum-length sparse array, and a second field then pushes past that length, which throws inside the append-field dependency and is not caught by multer. All versions before 2.3.0 are affected, and the issue is a remotely triggerable denial of service. The issue is fixed in multer 2.3.0. Upgrade to multer 2.3.0 to remediate.","status":"published","published":"2026-08-28T22:16:53.883Z","modified":"2026-09-02T14:46:28.59Z","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-248"],"updated_at":"2026-11-02T14:12:42.366888Z"}],"osv":[{"id":"CVE-2026-77078","title":"multer vulnerable to Denial of Service via crafted multipart field names","description":"multer is a middleware for handling multipart/form-data in Node.js. A small multipart request containing two specially crafted text field names can cause an uncaught RangeError (Invalid array length) that terminates the Node.js process. The first field uses a very large numeric array index to allocate a maximum-length sparse array, and a second field then pushes past that length, which throws inside the append-field dependency and is not caught by multer. All versions before 2.3.0 are affected, and the issue is a remotely triggerable denial of service. The issue is fixed in multer 2.3.0. Upgrade to multer 2.3.0 to remediate.","status":"published","published":"2026-08-28T20:03:23.114Z","modified":"2026-10-28T02:30:47.490329163Z","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-248"],"updated_at":"2026-11-02T15:45:17.102988Z"},{"id":"DEBIAN-CVE-2026-77078","description":"multer is a middleware for handling multipart/form-data in Node.js. A small multipart request containing two specially crafted text field names can cause an uncaught RangeError (Invalid array length) that terminates the Node.js process. The first field uses a very large numeric array index to allocate a maximum-length sparse array, and a second field then pushes past that length, which throws inside the append-field dependency and is not caught by multer. All versions before 2.3.0 are affected, and the issue is a remotely triggerable denial of service. The issue is fixed in multer 2.3.0. Upgrade to multer 2.3.0 to remediate.","status":"published","published":"2026-08-28T22:16:53.883Z","modified":"2026-11-02T18:00:46.382068382Z","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":"2026-11-02T19:03:20.122208Z"},{"id":"GHSA-wc9g-mqfw-jrwm","title":"multer vulnerable to Denial of Service via crafted multipart field names","description":"### Impact\n\nA vulnerability in multer allows a remote, unauthenticated attacker to crash the Node.js process with a single `multipart/form-data` request. Two specially crafted text field names cause an uncaught `RangeError: Invalid array length` inside multer's field parsing, which is not routed to the application error handler and terminates the process. All applications using multer to parse multipart requests are affected.\n\n### Patches\n\nUsers should upgrade to `2.3.0`.\n\n### Workarounds\n\nNone.","status":"published","published":"2026-09-08T21:30:20Z","modified":"2026-09-08T21:45:04.624532917Z","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-248"],"updated_at":"2026-11-02T15:46:58.401149Z"},{"id":"CLSA-2026-1788988502","title":"TuxCare security update for multer (2 CVEs)","description":"TuxCare rebuilt multer to address 2 CVEs. Fixed in 1.4.5-lts.2-tuxcare.5.","status":"published","published":"2026-09-09T21:15:02Z","modified":"2026-10-15T09:47:55.712869518Z","updated_at":"2026-11-02T15:43:47.938828Z"},{"id":"CLSA-2026-1790176219","title":"TuxCare security update for multer (2 CVEs)","description":"TuxCare rebuilt multer to address 2 CVEs. Fixed in 1.4.5-lts.1-tuxcare.9.","status":"published","published":"2026-09-23T15:10:19Z","modified":"2026-10-15T09:47:56.494183839Z","updated_at":"2026-11-02T15:43:48.28229Z"},{"id":"CLSA-2026-1790604779","title":"TuxCare security update for multer (2 CVEs)","description":"TuxCare rebuilt multer to address 2 CVEs. Fixed in 2.2.0-tuxcare.1.","status":"published","published":"2026-09-28T14:12:59Z","modified":"2026-10-15T09:48:03.10815253Z","updated_at":"2026-11-02T15:43:48.65893Z"},{"id":"ROOT-APP-NPM-CVE-2026-77078","title":"CVE-2026-77078 in multer - Patched by Root","description":"Root has patched CVE-2026-77078 in the multer package for Root:npm. Multiple fixed versions available.","status":"published","published":"2026-11-04T08:05:48Z","modified":"2026-11-04T09:15:05.222900751Z","updated_at":"2026-11-04T09:34:03.871859Z"}]}}