CVE-2026-48688

NameCVE-2026-48688
DescriptionFastNetMon Community Edition through 1.2.9 contains multiple out-of-bounds reads in the BGP MP_REACH_NLRI IPv6 attribute decoder. The function decode_mp_reach_ipv6() in src/bgp_protocol.cpp contains a TODO comment at line 156 explicitly acknowledging 'we should add sanity checks to avoid reads after attribute memory block.' The function casts raw pointers to structure types without verifying sufficient data exists (line 158), uses the attacker-controlled length_of_next_hop field to determine memcpy size (line 181), and computes prefix_length by dereferencing a pointer calculated from multiple attacker-controlled offsets without bounds validation (line 189). The prefix_length is then used to calculate number_of_bytes_required_for_prefix which becomes a memcpy length (line 202) with no check against remaining buffer size.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
fastnetmon (PTS)bookworm, bookworm (security)1.2.4-2+deb12u1vulnerable
trixie1.2.8-1vulnerable
forky, sid1.2.8+git20250911-2vulnerable

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
fastnetmonsource(unstable)(unfixed)

Notes

https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48688-bgp-mp-reach-nlri-ipv6
https://github.com/pavel-odintsov/fastnetmon/commit/04e26ac2e0861efe7a50f3c3fd27e57f840aa4a3
https://github.com/pavel-odintsov/fastnetmon/pull/1055

Search for package or bug name: Reporting problems