Out-of-bounds read in FastNetMon - #VU138930
Published: July 21, 2026
Vulnerability identifier: #VU138930
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to out-of-bounds read in netflow9_options_flowset_to_store() when processing the NETFLOW9_INTERFACE_DESCRIPTION field in NetFlow v9 packets. A remote attacker can send a specially crafted UDP packet to cause a denial of service.
The issue is reachable through the live UDP collector, and a single crafted packet without a null terminator in the interface-description field can trigger the crash.
Affected software
FastNetMon
Remediation
Cybersecurity Help is not aware of any official solution to address this vulnerability.