CVE-2026-48688

Out-of-Bounds Read in FastNetMon BGP IPv6 Parser

Published May 26, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
FastNetMon 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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DSA Debian DSA DSA-6375-1 fastnetmon security update
History
Type Values Removed Values Added
CPEs cpe:2.3:a:pavel-odintsov:fastnetmon:*:*:*:*:community:*:*:*
Type Values Removed Values Added
Title Out-of-Bounds Read in FastNetMon BGP IPv6 Parser
Type Values Removed Values Added
Title FastNetMon Community Edition BGP MP_REACH_NLRI IPv6 Decoder Out-of-Bounds Read
Weaknesses CWE-200
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title FastNetMon Community Edition BGP MP_REACH_NLRI IPv6 Decoder Out-of-Bounds Read
First Time appeared Pavel-odintsov
Pavel-odintsov fastnetmon
Weaknesses CWE-125
CWE-200
Vendors & Products Pavel-odintsov
Pavel-odintsov fastnetmon
Type Values Removed Values Added
Description FastNetMon 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.
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
May 26, 2026, 8:52 PM
Reserved
May 22, 2026, 12:00 AM
Status
Analyzed
Published
May 26, 2026, 4:16 PM
Modified
Jul 24, 2026, 11:10 AM