# CVE-2026-31594: PCI: endpoint: pci-epf-vntb: Remove duplicate resource teardown

> A duplicate resource teardown in the Linux kernel PCI endpoint driver causes a use-after-free error, leading to a system crash.

- **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:** 24 Apr 2026
- **Updated:** 14 Jun 2026
- **Also known as:** AZL-83777, BELL-CVE-2026-31594, DEBIAN-CVE-2026-31594, GHSA-9mvc-6grp-8hgm, ROOT-OS-DEBIAN-11-CVE-2026-31594, ROOT-OS-DEBIAN-12-CVE-2026-31594, ROOT-OS-DEBIAN-13-CVE-2026-31594, ROOT-OS-UBUNTU-2204-CVE-2026-31594, ROOT-OS-UBUNTU-2404-CVE-2026-31594, UBUNTU-CVE-2026-31594

## What is CVE-2026-31594?

CVE-2026-31594 is a medium-severity use after free vulnerability in Linux kernel, published on 24 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:

PCI: endpoint: pci-epf-vntb: Remove duplicate resource teardown

epf_ntb_epc_destroy() duplicates the teardown that the caller is
supposed to perform later. This leads to an oops when .allow_link fails
or when .drop_link is performed. The following is an example oops of the
former case:

  Unable to handle kernel paging request at virtual address dead000000000108
  [...]
  [dead000000000108] address between user and kernel address ranges
  Internal error: Oops: 0000000096000044 [#1]  SMP
  [...]
  Call trace:
   pci_epc_remove_epf+0x78/0xe0 (P)
   pci_primary_epc_epf_link+0x88/0xa8
   configfs_symlink+0x1f4/0x5a0
   vfs_symlink+0x134/0x1d8
   do_symlinkat+0x88/0x138
   __arm64_sys_symlinkat+0x74/0xe0
  [...]

Remove the helper, and drop pci_epc_put(). EPC device refcounting is
tied to the configfs EPC group lifetime, and pci_epc_put() in the
.drop_link path is sufficient.

## Which versions are affected by CVE-2026-31594?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-31594?

Apply the vendor's patch.

## Is CVE-2026-31594 being exploited?

There is no known exploitation of CVE-2026-31594 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-2026-31594 and fix it if it is affected.

What it is: CVE-2026-31594 is a medium-severity use after free vulnerability in Linux kernel, published on 24 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-2026-31594 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-2026-31594/ (Markdown: https://insights.sbomify.com/CVE-2026-31594/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31594
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31594
- OSV: https://osv.dev/vulnerability/CVE-2026-31594

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31594/
Summaries are generated and may contain mistakes; the official description above is the record.