# CVE-2026-43200: PCI: endpoint: Fix swapped parameters in pci_{primary/secondary}_epc_epf_unlink() functions

> A parameter swap in Linux kernel PCI endpoint unlink functions causes a kernel crash, leading to denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 6 May 2026
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2026-43200, DEBIAN-CVE-2026-43200, GHSA-h3wc-x575-rqjq, ROOT-OS-UBUNTU-2204-CVE-2026-43200, ROOT-OS-UBUNTU-2404-CVE-2026-43200, UBUNTU-CVE-2026-43200

## What is CVE-2026-43200?

CVE-2026-43200 is a medium-severity vulnerability in Linux kernel, published on 6 May 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:

PCI: endpoint: Fix swapped parameters in pci_{primary/secondary}_epc_epf_unlink() functions

struct configfs_item_operations callbacks are defined like the following:

  int (*allow_link)(struct config_item *src, struct config_item *target);
  void (*drop_link)(struct config_item *src, struct config_item *target);

While pci_primary_epc_epf_link() and pci_secondary_epc_epf_link() specify
the parameters in the correct order, pci_primary_epc_epf_unlink() and
pci_secondary_epc_epf_unlink() specify the parameters in the wrong order,
leading to the below kernel crash when using the unlink command in
configfs:

  Unable to handle kernel paging request at virtual address 0000000300000857
  Mem abort info:
  ...
  pc : string+0x54/0x14c
  lr : vsnprintf+0x280/0x6e8
  ...
  string+0x54/0x14c
  vsnprintf+0x280/0x6e8
  vprintk_default+0x38/0x4c
  vprintk+0xc4/0xe0
  pci_epf_unbind+0xdc/0x108
  configfs_unlink+0xe0/0x208+0x44/0x74
  vfs_unlink+0x120/0x29c
  __arm64_sys_unlinkat+0x3c/0x90
  invoke_syscall+0x48/0x134
  do_el0_svc+0x1c/0x30prop.0+0xd0/0xf0

[mani: cced stable, changed commit message as per https://lore.kernel.org/linux-pci/aV9joi3jF1R6ca02@ryzen]

## Which versions are affected by CVE-2026-43200?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-43200?

Apply the vendor's patch.

## Is CVE-2026-43200 being exploited?

There is no known exploitation of CVE-2026-43200 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-2026-43200 and fix it if it is affected.

What it is: CVE-2026-43200 is a medium-severity vulnerability in Linux kernel, published on 6 May 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-2026-43200 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-2026-43200/ (Markdown: https://insights.sbomify.com/CVE-2026-43200/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43200
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43200
- OSV: https://osv.dev/vulnerability/CVE-2026-43200

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-43200/
Summaries are generated and may contain mistakes; the official description above is the record.