Out-of-bounds read in FastNetMon - #VU138931
Published: July 21, 2026
Vulnerability identifier: #VU138931
CSH Severity: High
CVSS v4: 8.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/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 disclose sensitive information and cause a denial of service.
The vulnerability exists due to out-of-bounds read in parse_raw_packet_to_simple_packet_full() when parsing an IPv6 Fragment extension header. A remote attacker can send a specially crafted packet to disclose sensitive information and cause a denial of service.
The issue is reachable remotely and unauthenticated via a single crafted sFlow v5 UDP packet through RAW_PACKET_HEADER record handling.
Affected software
FastNetMon
Remediation
Cybersecurity Help is not aware of any official solution to address this vulnerability.