CVE-2026-92693
FastNetMon: IPv6 Fragment header dereferenced without bounds check in shared packet parser
What happened?
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.
Affected software and versions
| Software | Version information | Fixed version |
|---|---|---|
| fastnetmonpavel-odintsov | affected: <= 1.2.9 | See vendor advisory |
Version information comes from the source record and can include unaffected products and exceptions. Distribution packages may contain backported fixes: an older upstream version alone does not prove a server is affected.
Is it being exploited?
This CVE was not listed in the CISA catalogue at our last retrieval. This does not establish that exploitation is absent.
How to respond
- Confirm the product, installed package version, and any configuration requirements in the vendor advisory.
- Follow the vendor’s remediation or workaround guidance in the references below. Structured fixed-version data is unavailable here; the publisher’s description may include a fix or workaround.
- Restart affected services if required, then verify the running version. Known exploitation may warrant investigation as well as patching.