Buffer overflow in Pavel-odintsov Fastnetmon

CVE-2026-48691

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_segm…

Vulnerability class: Integer Overflow

EPSS: 0.001 (17.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-48691?
CVE-2026-48691 is a critical-severity vulnerability in Pavel-odintsov Fastnetmon, classified under Integer Overflow or Wraparound. CVSS score: 9.8/10. Published 2026-05-26.
How severe is CVE-2026-48691?
Critical severity. CVSS v3 base score is 9.8 out of 10.