CVE-2026-48691 Integer overflow in n/a
An integer overflow in FastNetMon's BGP encoder allows heap buffer overflows, potentially leading to remote code execution or service crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-48691?
CVE-2026-48691 is a high-severity vulnerability in n/a, published on 26 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
FastNetMon Community Edition through 1.2.9 contains an integer overflow in the BGP AS_PATH attribute encoder. In src/bgp_protocol.hpp, the IPv4UnicastAnnounce::get_attributes() function computes attribute_length as 'sizeof(bgp_as_path_segment_element_t) + this->as_path_asns.size() * sizeof(uint32_t)' and stores it in a uint8_t field (line 600-605). Since uint8_t can only hold values 0-255, an AS_PATH containing more than 63 ASNs (2 + 64*4 = 258 > 255) causes silent truncation. The truncated length is used for buffer sizing, while the actual data written is the full untruncated amount, resulting in a heap buffer overflow. Similarly, the path_segment_length field at line 621 is also uint8_t, truncating with more than 255 ASNs.
Which versions are affected by CVE-2026-48691?
It affects 1 product.
Products include Pavel-Odintsov Fastnetmon.
How do I fix CVE-2026-48691?
Upgrade to a fixed version.
Is CVE-2026-48691 being exploited?
There is no known exploitation of CVE-2026-48691 in the wild and no public exploit code.
Other vulnerabilities in n/a
Sources
Also known as DEBIAN-CVE-2026-48691, GHSA-pjmc-gjwh-qr2w, UBUNTU-CVE-2026-48691.