{"id":"CVE-2026-121727","aliases":["DEBIAN-CVE-2026-121727","EUVD-2026-116585","GHSA-f33j-xw62-gm9f","UBUNTU-CVE-2026-121727"],"status":"published","title":"Kore before 4.3.0 Integer Underflow Memory Exhaustion via http_header_recv()","description":"Kore before 4.3.0 contains an integer underflow vulnerability in HTTP request body handling that allows unauthenticated attackers to bypass http_body_max by sending more body bytes than declared. Attackers can send oversized first segments over many concurrent POST, PUT or DELETE connections, wrapping content_length to grow buffers unbounded and exhaust worker memory.","severity":{"version":"4.0","score":8.7,"vector":"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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00389,"percentile":0.3353,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-191"],"published":"2026-11-03T22:55:33Z","modified":"2026-11-09T15:52:22Z","affected":[{"source":"osv","ecosystem":"Debian:12","package":"kore","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.1.0-6","4.2.3-1","4.2.3-2"]},{"source":"osv","ecosystem":"Debian:14","package":"kore","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.3-1","1.2.3-2","1.2.3-3","1.2.3-4","1.2.3-5","2.0.0-1","2.0.0-2","2.0.0-3","2.0.0-4","3.3.1-1","4.0.1-1","4.0.1-2","4.0.1-3","4.0.1-4","4.0.1-5","4.1.0-1","4.1.0-2","4.1.0-3","4.1.0-4","4.1.0-5","4.1.0-6","4.2.3-1","4.2.3-2"]},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"kore","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.3-1","1.2.3-2","1.2.3-3","1.2.3-4","1.2.3-5"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"kore","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.0-4","3.3.1-1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"kore","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.1.0-3","4.1.0-4","4.1.0-4ubuntu1","4.1.0-6"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"kore","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.1.0-6"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"kore","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.3-2","4.2.3-2build1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"kore","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.2.3-2"]}],"products":[{"vendor":"jorisvink","product":"kore"}],"references":[{"url":"https://github.com/jorisvink/kore/commit/1ff3c0f6f7973dc7fc8bf38369790ef2d8079b3b","tags":["patch","fix","report"]},{"url":"https://github.com/jorisvink/kore","tags":["product","package","report"]},{"url":"https://kore.io/releases/4.3.0","tags":["release-notes","advisory","report"]},{"url":"https://github.com/jorisvink/kore/blob/4.3.0-rc5/src/http.c#L934","tags":["technical-description","article","report"]},{"url":"https://www.vulncheck.com/advisories/kore-before-4.3.0-integer-underflow-memory-exhaustion-via-http-header-recv","tags":["third-party-advisory","advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121727","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-f33j-xw62-gm9f"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/121xxx/CVE-2026-121727.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-121727","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-121727","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-121727","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-121727","title":"Kore before 4.3.0 Integer Underflow Memory Exhaustion via http_header_recv()","description":"Kore before 4.3.0 contains an integer underflow vulnerability in HTTP request body handling that allows unauthenticated attackers to bypass http_body_max by sending more body bytes than declared. Attackers can send oversized first segments over many concurrent POST, PUT or DELETE connections, wrapping content_length to grow buffers unbounded and exhaust worker memory.","status":"published","published":"2026-11-03T22:55:33.948Z","modified":"2026-11-09T15:52:22.218Z","cvss":[{"version":"4.0","score":8.7,"vector":"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","level":"high","assessor":"cna"},{"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-191"],"updated_at":"2026-11-09T16:33:53.922525Z"}],"euvd":[{"id":"EUVD-2026-116585","description":"Kore before 4.3.0 contains an integer underflow vulnerability in HTTP request body handling that allows unauthenticated attackers to bypass http_body_max by sending more body bytes than declared. Attackers can send oversized first segments over many concurrent POST, PUT or DELETE connections, wrapping content_length to grow buffers unbounded and exhaust worker memory.","status":"published","published":"2026-11-03T22:55:33Z","modified":"2026-11-09T15:52:22Z","cvss":[{"version":"4.0","score":8.7,"vector":"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","level":"high"}],"updated_at":"2026-11-09T17:17:30.806151Z"}],"ghsa":[{"id":"GHSA-f33j-xw62-gm9f","title":"Kore before 4.3.0 contains an integer underflow vulnerability in HTTP request body handling that...","description":"Kore before 4.3.0 contains an integer underflow vulnerability in HTTP request body handling that allows unauthenticated attackers to bypass http_body_max by sending more body bytes than declared. Attackers can send oversized first segments over many concurrent POST, PUT or DELETE connections, wrapping content_length to grow buffers unbounded and exhaust worker memory.","status":"published","published":"2026-11-04T00:32:17Z","modified":"2026-11-04T00:32:24Z","cvss":[{"version":"4.0","score":8.7,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"},{"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-191"],"updated_at":"2026-11-04T00:48:26.298057Z"}],"nvd":[{"id":"CVE-2026-121727","description":"Kore before 4.3.0 contains an integer underflow vulnerability in HTTP request body handling that allows unauthenticated attackers to bypass http_body_max by sending more body bytes than declared. Attackers can send oversized first segments over many concurrent POST, PUT or DELETE connections, wrapping content_length to grow buffers unbounded and exhaust worker memory.","status":"published","published":"2026-11-03T23:17:36.043Z","modified":"2026-11-12T21:36:06.743Z","cvss":[{"version":"4.0","score":8.7,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"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-191"],"updated_at":"2026-11-09T18:15:13.94391Z"}],"osv":[{"id":"CVE-2026-121727","title":"Kore before 4.3.0 Integer Underflow Memory Exhaustion via http_header_recv()","description":"Kore before 4.3.0 contains an integer underflow vulnerability in HTTP request body handling that allows unauthenticated attackers to bypass http_body_max by sending more body bytes than declared. Attackers can send oversized first segments over many concurrent POST, PUT or DELETE connections, wrapping content_length to grow buffers unbounded and exhaust worker memory.","status":"published","published":"2026-11-03T22:55:33.948Z","modified":"2026-11-11T13:21:03.459368626Z","cvss":[{"version":"4.0","score":8.7,"vector":"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","level":"high"}],"cwes":["CWE-191"],"updated_at":"2026-11-10T02:45:42.584685Z"},{"id":"DEBIAN-CVE-2026-121727","description":"Kore before 4.3.0 contains an integer underflow vulnerability in HTTP request body handling that allows unauthenticated attackers to bypass http_body_max by sending more body bytes than declared. Attackers can send oversized first segments over many concurrent POST, PUT or DELETE connections, wrapping content_length to grow buffers unbounded and exhaust worker memory.","status":"published","published":"2026-11-03T23:17:36.043Z","modified":"2026-11-10T10:00:24.209669973Z","cvss":[{"version":"4.0","score":8.7,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"}],"updated_at":"2026-11-10T10:26:30.347596Z"},{"id":"UBUNTU-CVE-2026-121727","description":"Kore before 4.3.0 contains an integer underflow vulnerability in HTTP request body handling that allows unauthenticated attackers to bypass http_body_max by sending more body bytes than declared. Attackers can send oversized first segments over many concurrent POST, PUT or DELETE connections, wrapping content_length to grow buffers unbounded and exhaust worker memory.","status":"published","published":"2026-11-03T23:17:00Z","modified":"2026-11-05T11:46:32.359570053Z","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"},{"version":"4.0","score":8.7,"vector":"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","level":"high"}],"updated_at":"2026-11-05T13:30:15.321876Z"}]}}