CVE-2026-48683 Information disclosure in n/a
An out-of-bounds read in FastNetMon allows attackers to leak memory or crash the service via crafted NetFlow v9 packets.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-48683?
CVE-2026-48683 is a medium-severity vulnerability in n/a, published on 26 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
FastNetMon Community Edition through 1.2.9 contains an out-of-bounds read vulnerability in the NetFlow v9 data flowset processor. In src/netflow_plugin/netflow_v9_collector.cpp, the Data template branch (lines 1695-1702) iterates over flow records without performing a per-iteration bounds check against the packet end pointer. In contrast, the Options template branch (lines 1709-1719) correctly checks 'if (pkt + offset + field_template->total_length > packet_end)' before each iteration. The Data branch omits this check entirely. Since template definitions are sent by the network peer (and are unauthenticated UDP), an attacker can craft templates that cause the parser to read arbitrary memory past the packet buffer. This can leak sensitive memory contents or cause a crash.
Weakness: CWE-125
Which versions are affected by CVE-2026-48683?
How do I fix CVE-2026-48683?
Upgrade to a fixed version.
Is CVE-2026-48683 being exploited?
There is no known exploitation of CVE-2026-48683 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-48683, GHSA-242v-wx3w-qx8x, UBUNTU-CVE-2026-48683.