CVE-2026-48683: n/a
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.
AI Analysis
Technical Summary
The vulnerability in FastNetMon Community Edition (≤1.2.9) exists in the NetFlow v9 collector component, specifically in the Data template processing code. Unlike the Options template branch, the Data template branch iterates over flow records without verifying that the iteration stays within the packet buffer boundaries. Since NetFlow templates are sent over unauthenticated UDP, an attacker can craft malicious templates that trigger out-of-bounds reads. This can lead to disclosure of sensitive memory or cause the application to crash due to invalid memory access. The vulnerability is identified as CVE-2026-48683 and was published on 2026-05-26. No CVSS score or patch information is currently available.
Potential Impact
An attacker can exploit this vulnerability by sending specially crafted NetFlow v9 templates to the FastNetMon service, causing it to read memory beyond the packet buffer. This can result in leakage of sensitive memory contents or cause the application to crash, potentially leading to denial of service. Since the UDP packets are unauthenticated, exploitation does not require prior access or authentication. No known exploits have been reported in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider restricting or filtering NetFlow v9 traffic sources to trusted peers to reduce exposure. Monitor for updates from FastNetMon regarding patches or official mitigations.
CVE-2026-48683: n/a
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.
CVSS v3.1
Score 6.5medium
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in FastNetMon Community Edition (≤1.2.9) exists in the NetFlow v9 collector component, specifically in the Data template processing code. Unlike the Options template branch, the Data template branch iterates over flow records without verifying that the iteration stays within the packet buffer boundaries. Since NetFlow templates are sent over unauthenticated UDP, an attacker can craft malicious templates that trigger out-of-bounds reads. This can lead to disclosure of sensitive memory or cause the application to crash due to invalid memory access. The vulnerability is identified as CVE-2026-48683 and was published on 2026-05-26. No CVSS score or patch information is currently available.
Potential Impact
An attacker can exploit this vulnerability by sending specially crafted NetFlow v9 templates to the FastNetMon service, causing it to read memory beyond the packet buffer. This can result in leakage of sensitive memory contents or cause the application to crash, potentially leading to denial of service. Since the UDP packets are unauthenticated, exploitation does not require prior access or authentication. No known exploits have been reported in the wild at this time.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, consider restricting or filtering NetFlow v9 traffic sources to trusted peers to reduce exposure. Monitor for updates from FastNetMon regarding patches or official mitigations.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-05-22T00:00:00.000Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a15c089891d628fdc570d28
Added to database: 5/26/2026, 3:47:21 PM
Last enriched: 5/26/2026, 4:03:04 PM
Last updated: 5/26/2026, 10:51:59 PM
Views: 6
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.