# CVE-2026-74340: wifi: wcn36xx: fix OOB read from firmware count in PRINT_REG_INFO indication

> A malicious firmware response can trigger an out-of-bounds read in the wcn36xx Wi-Fi driver, potentially leaking kernel memory or causing a crash.

- **Severity:** High 8.1 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H`)
- **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:** BELL-CVE-2026-74340, DEBIAN-CVE-2026-74340, GHSA-9fwg-3fvg-fm8h, UBUNTU-CVE-2026-74340

## What is CVE-2026-74340?

CVE-2026-74340 is a high-severity memory corruption 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:

wifi: wcn36xx: fix OOB read from firmware count in PRINT_REG_INFO indication

The firmware-controlled rsp->count field is used as the loop bound for
indexing into the flexible rsp->regs[] array without validation against
the message length. A count exceeding the actual data causes out-of-
bounds reads from the heap-allocated message buffer.

Add a check that count fits within the received message.

## Which versions are affected by CVE-2026-74340?


## How do I fix CVE-2026-74340?

Apply the vendor's patch.

## Is CVE-2026-74340 being exploited?

There is no known exploitation of CVE-2026-74340 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74340 and fix it if it is affected.

What it is: CVE-2026-74340 is a high-severity memory corruption 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-2026-74340 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-2026-74340/ (Markdown: https://insights.sbomify.com/CVE-2026-74340/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74340
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74340
- OSV: https://osv.dev/vulnerability/CVE-2026-74340

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74340/
Summaries are generated and may contain mistakes; the official description above is the record.