{"affected":[{"defaultStatus":"unaffected","product":"ipfixcol2","source":"CNA: VulnCheck","vendor":"CESNET","versions":[{"lessThan":"2.9.0","status":"affected","version":"2.7.1","versionType":"semver"}]}],"cveId":"CVE-2026-122129","cwes":["CWE-789"],"description":"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.","epss":null,"exploits":[],"kev":null,"metrics":[{"score":6.9,"severity":"medium","source":"CNA: VulnCheck","vector":"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","version":"4.0"},{"score":5.3,"severity":"medium","source":"CNA: VulnCheck","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","version":"3.1"}],"modifiedAt":1793824609660,"publishedAt":1793824609660,"references":[{"source":"CNA: VulnCheck","tags":["patch"],"url":"https://github.com/CESNET/ipfixcol2/commit/1a199033eff847941353c5c039cb806a9ad8aa6f"},{"source":"CNA: VulnCheck","tags":["product"],"url":"https://github.com/CESNET/ipfixcol2"},{"source":"CNA: VulnCheck","tags":["release-notes"],"url":"https://github.com/CESNET/ipfixcol2/releases/tag/v2.9.0"},{"source":"CNA: VulnCheck","tags":["technical-description"],"url":"https://github.com/CESNET/ipfixcol2/blob/v2.8.0/src/plugins/input/tcp/src/Lz4Decoder.cpp#L126-L131"},{"source":"CNA: VulnCheck","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/cesnet-ipfixcol2-2.7.1-before-2.9.0-memory-exhaustion-via-tcp-lz4-decoder"}],"remediation":[{"kind":"fix","source":"CNA: VulnCheck","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/CESNET/ipfixcol2/commit/1a199033eff847941353c5c039cb806a9ad8aa6f"}],"revision":"724906046df271d355fc9d29f9083b961dce19d4687bb4de51574a71661a073b","sources":[{"modifiedAt":1793824609660,"name":"CNA: VulnCheck","retrievedAt":1793826721733,"url":"https://www.cve.org/CVERecord?id=CVE-2026-122129"}],"ssvc":null,"status":"published","title":"CESNET ipfixcol2 2.7.1 before 2.9.0 Memory Exhaustion via TCP LZ4 Decoder","updatedAt":1793826721733}