{"id":"UBUNTU-CVE-2026-122129","details":"CESNET ipfixcol2 2.7.1 before 2.9.0 contains a memory allocation vulnerability in Lz4Decoder::read_start_header() that allows unauthenticated attackers to exhaust memory by declaring unbounded ring buffer sizes. Attackers can open TCP connections sending LZ4 start headers with very large buffer sizes, forcing up to 4 GiB allocations per connection and denying collector service.","modified":"2026-11-06T01:00:41.983066501Z","published":"2026-11-05T00:00:00Z","upstream":["CVE-2026-122129"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-122129"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-122129"},{"type":"REPORT","url":"https://github.com/CESNET/ipfixcol2"},{"type":"REPORT","url":"https://github.com/CESNET/ipfixcol2/blob/v2.8.0/src/plugins/input/tcp/src/Lz4Decoder.cpp#L126-L131"},{"type":"REPORT","url":"https://github.com/CESNET/ipfixcol2/commit/1a199033eff847941353c5c039cb806a9ad8aa6f"},{"type":"REPORT","url":"https://github.com/CESNET/ipfixcol2/releases/tag/v2.9.0"},{"type":"REPORT","url":"https://www.vulncheck.com/advisories/cesnet-ipfixcol2-2.7.1-before-2.9.0-memory-exhaustion-via-tcp-lz4-decoder"}],"affected":[{"package":{"name":"ipfixcol2","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/ipfixcol2?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.8.0+20260519-1","2.8.0+20260519-2","2.8.0+20260701-1"],"ecosystem_specific":{"binaries":[{"binary_name":"ipfixcol2","binary_version":"2.8.0+20260701-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-122129.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"},{"type":"Ubuntu","score":"medium"}]}