CVE-2026-122129mediumCWE-789

CVE-2026-122129: medium-severity vulnerability in CESNET ipfixcol2

CESNET ipfixcol2 2.7.1 before 2.9.0 Memory Exhaustion via TCP LZ4 Decoder

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13Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 6.9epss 0.4%
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.
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
Affected products
CESNET · ipfixcol2
Related CVEs — CESNET ipfixcol2

In the same product, most dangerous first.

CVE-2026-122127HIGHCESNET ipfixcol2 2.7.1 before 2.9.0 Heap Buffer Overflow via TCP LZ4 DecoderEPSS 0.4%CVE-2026-122130HIGHCESNET ipfixcol2 2.3.0 before 2.9.0 Buffer Overflow via Forwarder Output PluginEPSS 0.3%