Bug 2567616 (CVE-2026-122127)

Summary: CVE-2026-122127 ipfixcol2: ipfixcol2: Denial of Service via heap-based buffer overflow in LZ4 decoder
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in ipfixcol2. A heap-based buffer overflow in the LZ4 decompression component allows an unauthenticated remote attacker to cause a Denial of Service (DoS) by crashing the collector service. By sending network traffic that specifies a small buffer size alongside a disproportionately large decompressed data size, the attacker can trigger an out-of-bounds memory write.
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Description OSIDB Bzimport 2026-11-05 22:12:23 UTC 
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.