CVE-2026-48690 Integer overflow in n/a
An integer overflow in FastNetMon allows heap corruption and potential code execution if the ban_details_records_count configuration is set to a high value.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-48690?
CVE-2026-48690 is a high-severity vulnerability in n/a, published on 26 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-48690?
It affects 1 product.
Products include Pavel-Odintsov Fastnetmon.
How do I fix CVE-2026-48690?
Upgrade to a fixed version.
Is CVE-2026-48690 being exploited?
There is no known exploitation of CVE-2026-48690 in the wild and no public exploit code.
Other vulnerabilities in n/a
Sources
Also known as DEBIAN-CVE-2026-48690, GHSA-h9r4-jj3x-8857, UBUNTU-CVE-2026-48690.