CVE-2025-67499

Background

The CNI portmap plugin allows containers to emulate opening a host port, forwarding that traffic to the container. For example, if a host has the IP 198.51.100.42, a container may request that all packets to 198.51.100.42:53 be forwarded to the container's network.

Vulnerability

When the portmap plugin is configured with the nftables backend, it inadvertently forwards all traffic with the same destination port as the host port, ignoring the destination IP. This includes traffic not intended for the node itself, i.e. traffic to containers hosted on the node.

In the given example above, traffic destined to port 53 but for a separate container would still be captured and forwarded, even though it was not destined for the host.

Workarounds

Configure the portmap plugin to use the iptables backend. It does not have this vulnerability.

Containers (i.e. kubernetes pods) that request HostPort forwarding can intercept all traffic destined for that port. This requires that the portmap plugin be explicitly configured to use the nftables backend. (The iptables backend is the default.)

CVE-2025-67499 has a CVSS score of 6.6 (Medium). The vector is requires local access, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.9.0); upgrading removes the vulnerable code path.

Kodem intelligence

This is fixed as of CNI plugins v1.9.0

1. What is CVE-2025-67499? CVE-2025-67499 is a medium-severity security vulnerability in github.com/containernetworking/plugins (go), affecting versions >= 1.6.0, < 1.9.0. It is fixed in 1.9.0.
2. How severe is CVE-2025-67499? CVE-2025-67499 has a CVSS score of 6.6 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of github.com/containernetworking/plugins are affected by CVE-2025-67499? github.com/containernetworking/plugins (go) versions >= 1.6.0, < 1.9.0 is affected.
4. Is there a fix for CVE-2025-67499? Yes. CVE-2025-67499 is fixed in 1.9.0. Upgrade to this version or later.
5. Is CVE-2025-67499 exploitable, and should I be worried? Whether CVE-2025-67499 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2025-67499 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2025-67499? Upgrade github.com/containernetworking/plugins to 1.9.0 or later.