CVE-2023-2156 Denial of service in Linux kernel (RPL protocol)

What is CVE-2023-2156?

CVE-2023-2156 is a high-severity denial of service vulnerability in Debian Debian Linux, published on 9 May 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A flaw was found in the networking subsystem of the Linux kernel within the handling of the RPL protocol. This issue results from the lack of proper handling of user-supplied data, which can lead to an assertion failure. This may allow an unauthenticated remote attacker to create a denial of service condition on the system.

Weakness: CWE-617

Which versions are affected by CVE-2023-2156?

It affects 4 products.

Products include Debian Debian Linux, Fedoraproject Fedora, Linux kernel, Redhat Enterprise Linux.

How do I fix CVE-2023-2156?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2023-2156 being exploited?

There is no known exploitation of CVE-2023-2156 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2023-2156, GHSA-7jf7-rx7v-xwqq, SUSE-SU-2023:3658-1, UBUNTU-CVE-2023-2156.