NVD security advisoryHigh
High advisory for CESNET ipfixcol2 2.7.1
CVE-2026-122127 · Reported 4 Nov 2026
Full advisory details, affected packages, severity context, and original source.
Affected technology
CESNET ipfixcol2 2.7.1Affected product
Advisory overview
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.
Related references
- https://github.com/CESNET/ipfixcol2
- https://github.com/CESNET/ipfixcol2/blob/v2.8.0/src/plugins/input/tcp/src/Lz4Decoder.cpp#L139-L151
- https://github.com/CESNET/ipfixcol2/commit/fd5cb168efb4b864d33f655174711b2779cef502
- https://github.com/CESNET/ipfixcol2/releases/tag/v2.9.0
- https://www.vulncheck.com/advisories/cesnet-ipfixcol2-2.7.1-before-2.9.0-heap-buffer-overflow-via-tcp-lz4-decoder