CVE-2026-53014 net/sched: act_mirred: fix wrong device for mac_header_xmit check in tcf_blockcast_redir

What is CVE-2026-53014?

CVE-2026-53014 is a medium-severity memory corruption vulnerability in Linux kernel, published on 24 Jun 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:

net/sched: act_mirred: fix wrong device for mac_header_xmit check in tcf_blockcast_redir

In tcf_blockcast_redir(), when iterating block ports to redirect packets to multiple devices, the mac_header_xmit flag is queried from the wrong device. The loop sends to dev_prev but queries dev_is_mac_header_xmit(dev) — which is the NEXT device in the iteration, not the one being sent to.

This causes tcf_mirred_to_dev() to make incorrect decisions about whether to push or pull the MAC header. When the block contains mixed device types (e.g., an ethernet veth and a tunnel device), intermediate devices get the wrong mac_header_xmit flag, leading to skb header corruption. In the worst case, skb_push_rcsum with an incorrect mac_len can exhaust headroom and panic.

The last device in the loop is handled correctly (line 365-366 uses dev_is_mac_header_xmit(dev_prev)), confirming this is a copy-paste oversight for the intermediate devices.

Fix by using dev_prev instead of dev for the mac_header_xmit query, consistent with the device actually being sent to.

Which versions are affected by CVE-2026-53014?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-53014?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-53014 being exploited?

There is no known exploitation of CVE-2026-53014 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 BELL-CVE-2026-53014, DEBIAN-CVE-2026-53014, GHSA-x2v8-3q4q-r8g6, ROOT-OS-UBUNTU-2404-CVE-2026-53014, UBUNTU-CVE-2026-53014.