# CVE-2026-31502: team: fix header_ops type confusion with non-Ethernet ports

> A type confusion vulnerability in the Linux kernel team driver allows attackers to cause a system crash via crafted network packets.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 22 Apr 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-31502, DEBIAN-CVE-2026-31502, GHSA-pgcq-8hv5-frgj, ROOT-OS-DEBIAN-11-CVE-2026-31502, ROOT-OS-DEBIAN-12-CVE-2026-31502, ROOT-OS-DEBIAN-13-CVE-2026-31502, ROOT-OS-UBUNTU-2204-CVE-2026-31502, ROOT-OS-UBUNTU-2404-CVE-2026-31502, UBUNTU-CVE-2026-31502

## What is CVE-2026-31502?

CVE-2026-31502 is a high-severity memory corruption vulnerability in Linux kernel, published on 22 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:

team: fix header_ops type confusion with non-Ethernet ports

Similar to commit 950803f72547 ("bonding: fix type confusion in
bond_setup_by_slave()") team has the same class of header_ops type
confusion.

For non-Ethernet ports, team_setup_by_port() copies port_dev->header_ops
directly. When the team device later calls dev_hard_header() or
dev_parse_header(), these callbacks can run with the team net_device
instead of the real lower device, so netdev_priv(dev) is interpreted as
the wrong private type and can crash.

The syzbot report shows a crash in bond_header_create(), but the root
cause is in team: the topology is gre -> bond -> team, and team calls
the inherited header_ops with its own net_device instead of the lower
device, so bond_header_create() receives a team device and interprets
netdev_priv() as bonding private data, causing a type confusion crash.

Fix this by introducing team header_ops wrappers for create/parse,
selecting a team port under RCU, and calling the lower device callbacks
with port->dev, so each callback always sees the correct net_device
context.

Also pass the selected lower device to the lower parse callback, so
recursion is bounded in stacked non-Ethernet topologies and parse
callbacks always run with the correct device context.

Weakness: CWE-843 (Access of Resource Using Incompatible Type)

## Which versions are affected by CVE-2026-31502?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-31502?

Apply the vendor's patch.

## Is CVE-2026-31502 being exploited?

There is no known exploitation of CVE-2026-31502 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-31502 and fix it if it is affected.

What it is: CVE-2026-31502 is a high-severity memory corruption vulnerability in Linux kernel, published on 22 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-31502 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-31502/ (Markdown: https://insights.sbomify.com/CVE-2026-31502/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31502
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31502
- OSV: https://osv.dev/vulnerability/CVE-2026-31502

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31502/
Summaries are generated and may contain mistakes; the official description above is the record.