CVE-2026-48683 Affecting fastnetmon package, versions <1.2.9-1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DEBIANUNSTABLE-FASTNETMON-17089137
- published29 May 2026
- disclosed26 May 2026
Introduced: 26 May 2026
CVE-2026-48683 (opens in a new tab)How to fix?
Upgrade Debian:unstable fastnetmon to version 1.2.9-1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream fastnetmon package and not the fastnetmon package as distributed by Debian.
See How to fix? for Debian:unstable relevant fixed versions and status.
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.