# CVE-2026-45877: HID: intel-ish-hid: fix NULL-ptr-deref in ishtp_bus_remove_all_clients

> A NULL pointer dereference in the Intel ISH HID driver during warm resets can cause a kernel panic, 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:** 27 May 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-88637, BELL-CVE-2026-45877, DEBIAN-CVE-2026-45877, GHSA-69w2-j9pm-3jxm, ROOT-OS-DEBIAN-11-CVE-2026-45877, ROOT-OS-DEBIAN-12-CVE-2026-45877, ROOT-OS-UBUNTU-2204-CVE-2026-45877, ROOT-OS-UBUNTU-2404-CVE-2026-45877, UBUNTU-CVE-2026-45877

## What is CVE-2026-45877?

CVE-2026-45877 is a medium-severity vulnerability in Linux kernel, published on 27 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:

HID: intel-ish-hid: fix NULL-ptr-deref in ishtp_bus_remove_all_clients

During a warm reset flow, the cl->device pointer may be NULL if the
reset occurs while clients are still being enumerated. Accessing
cl->device->reference_count without a NULL check leads to a kernel panic.

This issue was identified during multi-unit warm reboot stress clycles.
Add a defensive NULL check for cl->device to ensure stability under
such intensive testing conditions.

KASAN: null-ptr-deref in range [0000000000000000-0000000000000007]
Workqueue: ish_fw_update_wq fw_reset_work_fn

Call Trace:
 ishtp_bus_remove_all_clients+0xbe/0x130 [intel_ishtp]
 ishtp_reset_handler+0x85/0x1a0 [intel_ishtp]
 fw_reset_work_fn+0x8a/0xc0 [intel_ish_ipc]

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-45877?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-45877?

Apply the vendor's patch.

## Is CVE-2026-45877 being exploited?

There is no known exploitation of CVE-2026-45877 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-2026-45877 and fix it if it is affected.

What it is: CVE-2026-45877 is a medium-severity vulnerability in Linux kernel, published on 27 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-2026-45877 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-2026-45877/ (Markdown: https://insights.sbomify.com/CVE-2026-45877/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45877
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45877
- OSV: https://osv.dev/vulnerability/CVE-2026-45877

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45877/
Summaries are generated and may contain mistakes; the official description above is the record.