CVE-2026-48690

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.

CVSS v3 7.1 HIGH

7.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.8 / Impact : 5.2

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/pavel-odintsov/fastnetmon	Product
https://github.com/pavel-odintsov/fastnetmon/blob/master/src/packet_storage.hpp	Product
https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48690-packet-storage-integer-overflow	Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:pavel-odintsov:fastnetmon:*:*:*:*:community:*:*:*

History

No history.

Information

Published : 2026-05-26 17:16

Updated : 2026-07-24 11:10

NVD link : CVE-2026-48690

Mitre link : CVE-2026-48690

CVE.ORG link : CVE-2026-48690

JSON object : View

Products Affected

pavel-odintsov

fastnetmon

CWE

CWE-122

Heap-based Buffer Overflow

CWE-190

Integer Overflow or Wraparound

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