{"id":"CVE-2026-122127","aliases":["DEBIAN-CVE-2026-122127","EUVD-2026-117082","GHSA-4575-chq4-crfc","UBUNTU-CVE-2026-122127"],"status":"published","title":"CESNET ipfixcol2 2.7.1 before 2.9.0 Heap Buffer Overflow via TCP LZ4 Decoder","description":"CESNET ipfixcol2 2.7.1 before 2.9.0 contains a heap-based buffer overflow in Lz4Decoder.cpp that allows unauthenticated network peers to write past heap buffers. Attackers can declare a small ring buffer_size followed by a large decompressed_size to write up to 65535 controlled bytes and crash the collector.","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":0.00387,"percentile":0.33245,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-787"],"published":"2026-11-04T20:36:48Z","modified":"2026-11-06T01:05:02Z","fixes":[{"ecosystem":"Debian:14","package":"ipfixcol2","fixed_in":["2.9.0-1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:14","package":"ipfixcol2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.9.0-1"}]}],"versions":["2.8.0+20260519-1","2.8.0+20260519-2","2.8.0+20260701-1","2.8.0+20260701-2"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"ipfixcol2","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.8.0+20260519-1","2.8.0+20260519-2","2.8.0+20260701-1"]}],"products":[{"vendor":"cesnet","product":"ipfixcol2"}],"references":[{"url":"https://github.com/CESNET/ipfixcol2/commit/fd5cb168efb4b864d33f655174711b2779cef502","tags":["patch","fix","report"]},{"url":"https://github.com/CESNET/ipfixcol2","tags":["product","package","report"]},{"url":"https://github.com/CESNET/ipfixcol2/releases/tag/v2.9.0","tags":["release-notes","advisory","report"]},{"url":"https://github.com/CESNET/ipfixcol2/blob/v2.8.0/src/plugins/input/tcp/src/Lz4Decoder.cpp#L139-L151","tags":["technical-description","article","report"]},{"url":"https://www.vulncheck.com/advisories/cesnet-ipfixcol2-2.7.1-before-2.9.0-heap-buffer-overflow-via-tcp-lz4-decoder","tags":["third-party-advisory","advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-122127","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-4575-chq4-crfc"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/122xxx/CVE-2026-122127.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-122127","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-122127","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-122127","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-122127","title":"CESNET ipfixcol2 2.7.1 before 2.9.0 Heap Buffer Overflow via TCP LZ4 Decoder","description":"CESNET ipfixcol2 2.7.1 before 2.9.0 contains a heap-based buffer overflow in Lz4Decoder.cpp that allows unauthenticated network peers to write past heap buffers. Attackers can declare a small ring buffer_size followed by a large decompressed_size to write up to 65535 controlled bytes and crash the collector.","status":"published","published":"2026-11-04T20:36:48.956Z","modified":"2026-11-05T19:36:14.196Z","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-787"],"updated_at":"2026-11-05T20:54:59.423743Z"}],"euvd":[{"id":"EUVD-2026-117082","description":"CESNET ipfixcol2 2.7.1 before 2.9.0 contains a heap-based buffer overflow in Lz4Decoder.cpp that allows unauthenticated network peers to write past heap buffers. Attackers can declare a small ring buffer_size followed by a large decompressed_size to write up to 65535 controlled bytes and crash the collector.","status":"published","published":"2026-11-04T20:36:48Z","modified":"2026-11-05T19:36:14Z","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":"2026-11-05T21:01:59.785126Z"}],"ghsa":[{"id":"GHSA-4575-chq4-crfc","title":"CESNET ipfixcol2 2.7.1 before 2.9.0 contains a heap-based buffer overflow in Lz4Decoder.cpp that...","description":"CESNET ipfixcol2 2.7.1 before 2.9.0 contains a heap-based buffer overflow in Lz4Decoder.cpp that allows unauthenticated network peers to write past heap buffers. Attackers can declare a small ring buffer_size followed by a large decompressed_size to write up to 65535 controlled bytes and crash the collector.","status":"published","published":"2026-11-04T21:32:31Z","modified":"2026-11-04T21:32:32Z","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-787"],"updated_at":"2026-11-04T21:42:45.289646Z"}],"nvd":[{"id":"CVE-2026-122127","description":"CESNET ipfixcol2 2.7.1 before 2.9.0 contains a heap-based buffer overflow in Lz4Decoder.cpp that allows unauthenticated network peers to write past heap buffers. Attackers can declare a small ring buffer_size followed by a large decompressed_size to write up to 65535 controlled bytes and crash the collector.","status":"published","published":"2026-11-04T21:18:08.2Z","modified":"2026-11-05T20:17:49.557Z","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-787"],"updated_at":"2026-11-05T21:56:49.714113Z"}],"osv":[{"id":"CVE-2026-122127","title":"CESNET ipfixcol2 2.7.1 before 2.9.0 Heap Buffer Overflow via TCP LZ4 Decoder","description":"CESNET ipfixcol2 2.7.1 before 2.9.0 contains a heap-based buffer overflow in Lz4Decoder.cpp that allows unauthenticated network peers to write past heap buffers. Attackers can declare a small ring buffer_size followed by a large decompressed_size to write up to 65535 controlled bytes and crash the collector.","status":"published","published":"2026-11-04T20:36:48.956Z","modified":"2026-11-07T07:02:54.879065379Z","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-787"],"updated_at":"2026-11-07T03:08:01.726202Z"},{"id":"DEBIAN-CVE-2026-122127","description":"CESNET ipfixcol2 2.7.1 before 2.9.0 contains a heap-based buffer overflow in Lz4Decoder.cpp that allows unauthenticated network peers to write past heap buffers. Attackers can declare a small ring buffer_size followed by a large decompressed_size to write up to 65535 controlled bytes and crash the collector.","status":"published","published":"2026-11-04T21:18:08.2Z","modified":"2026-11-06T10:06:23.971517126Z","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":"2026-11-06T10:38:22.758306Z"},{"id":"UBUNTU-CVE-2026-122127","description":"CESNET ipfixcol2 2.7.1 before 2.9.0 contains a heap-based buffer overflow in Lz4Decoder.cpp that allows unauthenticated network peers to write past heap buffers. Attackers can declare a small ring buffer_size followed by a large decompressed_size to write up to 65535 controlled bytes and crash the collector.","status":"published","published":"2026-11-05T00:00:00Z","modified":"2026-11-06T01:00:24.286717654Z","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":"2026-11-06T01:33:05.666804Z"}]}}