# CVE-2026-74507: Bluetooth: HIDP: validate numbered report payloads

> A malicious Bluetooth peer can trigger an uninitialized memory read in the Linux kernel HIDP driver, potentially leaking sensitive kernel memory.

- **Severity:** High 7.1 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** AZL-96255, BELL-CVE-2026-74507, DEBIAN-CVE-2026-74507, GHSA-m9hx-hxv2-v7fm, UBUNTU-CVE-2026-74507

## What is CVE-2026-74507?

CVE-2026-74507 is a high-severity vulnerability in Linux, published on 15 Aug 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:

Bluetooth: HIDP: validate numbered report payloads

When hidp_get_raw_report() waits for a numbered report,
hidp_process_data() compares the expected report number with skb->data[0].
A connected HIDP peer can reply with only a DATA transaction header,
leaving the skb empty after the header is removed.

KMSAN reports an uninitialized-value use in hidp_session_run(), with the
value originating in __alloc_skb() through vhci_write(). The transaction
header checks remove the empty-frame reports, but this report remains until
the payload check is added.

The comparison can also consume a peer-controlled byte beyond the declared
L2CAP PDU. A DATA | FEATURE response followed by an extra 0x01 byte made
the current code accept that byte as report ID 1 and complete
HIDIOCGFEATURE with a zero-byte result. With this change the malformed
response is rejected with -EIO, while a subsequent valid response still
succeeds.

Require a payload byte before comparing a numbered report ID. Unnumbered
reports continue to accept an empty payload.

## Which versions are affected by CVE-2026-74507?


## How do I fix CVE-2026-74507?

Apply the vendor's patch.

## Is CVE-2026-74507 being exploited?

There is no known exploitation of CVE-2026-74507 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74507 and fix it if it is affected.

What it is: CVE-2026-74507 is a high-severity vulnerability in Linux, published on 15 Aug 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-2026-74507 in the wild and no public exploit code.

Affected product: Linux. 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-2026-74507/ (Markdown: https://insights.sbomify.com/CVE-2026-74507/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74507
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74507
- OSV: https://osv.dev/vulnerability/CVE-2026-74507

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74507/
Summaries are generated and may contain mistakes; the official description above is the record.