Vulnerability · Published Nov 4, 2026 · Assigned by VulnCheck

CVE-2026-122130CESNET ipfixcol2 2.3.0 before 2.9.0 Buffer Overflow via Forwarder Output Plugin

High 8.2

In plain English

A high-severity integer overflow in ipfixcol2 from CESNET. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.2High

Exploit odds (30 days)0.3%top 75.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:14	ipfixcol2	2.9.0-1	DEBIAN-CVE-2026-122130
Ubuntu:26.10	ipfixcol2	no fix listed	UBUNTU-CVE-2026-122130

Affected products (as reported)

Vendor	Product	Versions
CESNET	ipfixcol2	2.3.0 – before 2.9.0

Weakness: CWE-190 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

References

Patch Commit patch
https://github.com/CESNET/ipfixcol2 product
ipfixcol2 v2.9.0 Release Notes release-notes
https://github.com/CESNET/ipfixcol2/blob/v2.8.0/src/plugins/output/forwarder/src/Message.cpp#L134-L156 technical-description
VulnCheck Advisory: CESNET ipfixcol2 2.3.0 before 2.9.0 Buffer Overflow via Forwarder Output Plugin third-party-advisory