CVE-2026-31679 openvswitch: validate MPLS set/set_masked payload length

What is CVE-2026-31679?

CVE-2026-31679 is a high-severity denial of service vulnerability in Linux kernel, published on 25 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

openvswitch: validate MPLS set/set_masked payload length

validate_set() accepted OVS_KEY_ATTR_MPLS as variable-sized payload for SET/SET_MASKED actions. In action handling, OVS expects fixed-size MPLS key data (struct ovs_key_mpls).

Use the already normalized key_len (masked case included) and reject non-matching MPLS action key sizes.

Reject invalid MPLS action payload lengths early.

Weakness: CWE-20

Which versions are affected by CVE-2026-31679?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-31679?

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-2026-31679 being exploited?

There is no known exploitation of CVE-2026-31679 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

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

Also known as AZL-84231, BELL-CVE-2026-31679, DEBIAN-CVE-2026-31679, GHSA-j5m6-467m-h4hw, ROOT-OS-DEBIAN-11-CVE-2026-31679, ROOT-OS-DEBIAN-12-CVE-2026-31679 and 3 more.