---
id: "CVE-2026-122130"
kind: "vulnerability"
aliases: ["CVE-2026-122130"]
title: "ipfixcol2: integer overflow in Forwarder plugin enables heap overflow"
severity: "high"
cvss: 8.3
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["ipfix", "ipfixcol2", "linux", "network-monitoring", "package"]
not_affected_if: ["no-forwarder-plugin", "version-2.9.0-or-later"]
published_at: "2026-11-04T21:18:08+00:00"
first_seen_at: "2026-11-04T21:49:19+00:00"
updated_at: "2026-11-04T21:50:43+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-122130", "first_seen_at": "2026-11-04T21:49:19+00:00"}]
exploit_sources: []
---

# ipfixcol2: integer overflow in Forwarder plugin enables heap overflow

CESNET ipfixcol2 before 2.9.0 has an integer overflow in its Forwarder output plugin, where uint16_t length counters wrap. An unauthenticated IPFIX exporter can overflow a heap buffer, crashing the collector and possibly writing attacker-chosen 2-byte values to memory.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed ipfixcol2 version, for example with `ipfixcol2 --version` or the package manager, and confirm whether it is below `2.9.0`.
- Look for a Forwarder output plugin in the collector configuration that forwards over TCP.

## Fix

- Upgrade ipfixcol2 to `2.9.0` or later.

## Timeline

- 2026-11-04T21:49:19+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-122130

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/cesnet-ipfixcol2-2.3.0-before-2.9.0-buffer-overflow-via-forwarder-output-plugin
- [fix] Patch: github.com https://github.com/CESNET/ipfixcol2/commit/ad206f6217257b06b139f1b2bce50d52f5bc6acb
- [fix] Release notes: github.com https://github.com/CESNET/ipfixcol2/releases/tag/v2.9.0

## From the sources

CESNET ipfixcol2 2.3.0 before 2.9.0 contains an integer overflow vulnerability in the Forwarder output plugin that allows unauthenticated IPFIX exporters to overflow a heap buffer by wrapping uint16_t message length counters. Attackers can send near-65535-byte data sets and large templates to a collector forwarding over TCP to crash it and perform 2-byte writes to attacker-influenced addresses.

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