Buffer overflow in Pavel-odintsov Fastnetmon

CVE-2026-48689

FastNetMon Community Edition through 1.2.9 contains an off-by-one heap-based buffer overflow in the dynamic_binary_buffer_t class (src/dynamic_binary_buffer.hpp). Five methods (append_dynamic_buffer, append_data_as_pointer, append_data_as_…

Vulnerability class: Buffer Overflow

EPSS: 0.000 (9.1th 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-2026-48689?
CVE-2026-48689 is a critical-severity vulnerability in Pavel-odintsov Fastnetmon, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2026-05-26.
How severe is CVE-2026-48689?
Critical severity. CVSS v3 base score is 9.8 out of 10.