CVE-2026-122127
CESNET ipfixcol2 2.7.1 before 2.9.0 Heap Buffer Overflow via TCP LZ4 Decoder
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-787 |
| Vendor | cesnet |
| Product | ipfixcol2 |
| Published | Nov 4, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
CESNET / ipfixcol2
2.7.1 < 2.9.0
References
github.com: https://github.com/CESNET/ipfixcol2/commit/fd5cb168efb4b864d33f655174711b2779cef502 github.com: https://github.com/CESNET/ipfixcol2 github.com: https://github.com/CESNET/ipfixcol2/releases/tag/v2.9.0 github.com: https://github.com/CESNET/ipfixcol2/blob/v2.8.0/src/plugins/input/tcp/src/Lz4Decoder.cpp#L139-L151 vulncheck.com: https://www.vulncheck.com/advisories/cesnet-ipfixcol2-2.7.1-before-2.9.0-heap-buffer-overflow-via-tcp-lz4-decoder
Credits
Deus Rex Michal Sedlak