# CVE-2025-71108: usb: typec: ucsi: Handle incorrect num_connectors capability

> A Linux kernel USB driver flaw allows buggy firmware to cause system boot failures, requiring a patch to handle invalid connector counts.

- **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:** 14 Jan 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2025-71108, DEBIAN-CVE-2025-71108, GHSA-6q3j-74vv-fx6w, ROOT-OS-UBUNTU-2204-CVE-2025-71108, ROOT-OS-UBUNTU-2404-CVE-2025-71108, UBUNTU-CVE-2025-71108

## What is CVE-2025-71108?

CVE-2025-71108 is a medium-severity denial of service vulnerability in Linux kernel, published on 14 Jan 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:

usb: typec: ucsi: Handle incorrect num_connectors capability

The UCSI spec states that the num_connectors field is 7 bits, and the
8th bit is reserved and should be set to zero.
Some buggy FW has been known to set this bit, and it can lead to a
system not booting.
Flag that the FW is not behaving correctly, and auto-fix the value
so that the system boots correctly.

Found on Lenovo P1 G8 during Linux enablement program. The FW will
be fixed, but seemed worth addressing in case it hit platforms that
aren't officially Linux supported.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2025-71108?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-71108?

Apply the vendor's patch.

## Is CVE-2025-71108 being exploited?

There is no known exploitation of CVE-2025-71108 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-2025-71108 and fix it if it is affected.

What it is: CVE-2025-71108 is a medium-severity denial of service vulnerability in Linux kernel, published on 14 Jan 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-2025-71108 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-2025-71108/ (Markdown: https://insights.sbomify.com/CVE-2025-71108/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-71108
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-71108
- OSV: https://osv.dev/vulnerability/CVE-2025-71108

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-71108/
Summaries are generated and may contain mistakes; the official description above is the record.