Bug 2567956 (CVE-2026-92693)

Summary: CVE-2026-92693 fastnetmon: FastNetMon: Denial of Service via crafted IPv6 packet header
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 FastNetMon. This vulnerability allows an unauthenticated remote attacker to cause a Denial of Service (DoS) or potentially disclose memory contents. By sending a crafted network packet record containing a truncated IPv6 fragment header, an attacker triggers an out-of-bounds memory read because the packet parser fails to verify that the required header bytes are present.
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Description OSIDB Bzimport 2026-11-05 22:41:50 UTC 
FastNetMon is a high-performance DDoS detector and sensor. In version 1.2.9 and earlier, parse_raw_packet_to_simple_packet_full() in src/simple_packet_parser_ng.cpp dereferences ipv6_extension_header_fragment_t when IpProtocolNumberIPV6_FRAG is present without first verifying that the eight-byte Fragment header remains. A crafted sFlow v5 RAW_PACKET_HEADER record can remotely reach this shared parser with the Fragment bytes omitted, causing an unauthenticated remote out-of-bounds read. The supplied harness detects the read under AddressSanitizer, but the advisory does not establish a production process crash. No fixed release is available as of this review.