CVE-2026-48690

Published May 26, 2026 CVSS 3.1 · 7.1 High EPSS < 1% KEV · Not listed
Description
FastNetMon Community Edition through 1.2.9 contains an integer overflow vulnerability in the packet capture buffer allocation. In src/packet_storage.hpp, the allocate_buffer() function computes memory_size_in_bytes as 'buffer_size_in_packets * (max_captured_packet_size + sizeof(fastnetmon_pcap_pkthdr_t)) + sizeof(fastnetmon_pcap_file_header_t)' using unsigned int (32-bit) arithmetic. With max_captured_packet_size=1500 and sizeof(fastnetmon_pcap_pkthdr_t)=16, each packet requires approximately 1516 bytes. If buffer_size_in_packets exceeds approximately 2,832,542, the multiplication overflows, resulting in a much smaller allocation than expected. Subsequent write_packet() calls then write past the allocated buffer, causing heap corruption. The buffer_size_in_packets value is derived from the ban_details_records_count configuration parameter, which is parsed using atoi() with no overflow checking.

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 Integer Overflow in FastNetMon Packet Storage Buffer Allocation
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Integer Overflow in FastNetMon Packet Storage Buffer Allocation
Weaknesses CWE-122
CWE-190
Type Values Removed Values Added
First Time appeared Pavel-odintsov
Pavel-odintsov fastnetmon
Vendors & Products Pavel-odintsov
Pavel-odintsov fastnetmon
Type Values Removed Values Added
Description FastNetMon Community Edition through 1.2.9 contains an integer overflow vulnerability in the packet capture buffer allocation. In src/packet_storage.hpp, the allocate_buffer() function computes memory_size_in_bytes as 'buffer_size_in_packets * (max_captured_packet_size + sizeof(fastnetmon_pcap_pkthdr_t)) + sizeof(fastnetmon_pcap_file_header_t)' using unsigned int (32-bit) arithmetic. With max_captured_packet_size=1500 and sizeof(fastnetmon_pcap_pkthdr_t)=16, each packet requires approximately 1516 bytes. If buffer_size_in_packets exceeds approximately 2,832,542, the multiplication overflows, resulting in a much smaller allocation than expected. Subsequent write_packet() calls then write past the allocated buffer, causing heap corruption. The buffer_size_in_packets value is derived from the ban_details_records_count configuration parameter, which is parsed using atoi() with no overflow checking.
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
May 26, 2026, 9:01 PM
Reserved
May 22, 2026, 12:00 AM
Status
Analyzed
Published
May 26, 2026, 5:16 PM
Modified
Jul 24, 2026, 11:10 AM