# CVE-2026-74297: RDMA/mlx5: Fix undefined shift of user RQ WQE size

> A local attacker can trigger undefined behavior via integer overflow in RDMA WQE size calculation, potentially causing denial of service or code execution.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 15 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-74297, DEBIAN-CVE-2026-74297, GHSA-p4jx-gh49-76wv, UBUNTU-CVE-2026-74297

## What is CVE-2026-74297?

CVE-2026-74297 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:

RDMA/mlx5: Fix undefined shift of user RQ WQE size

set_rq_size() computes the RQ WQE size as "1 << rq_wqe_shift" based on
the user-provided rq_wqe_shift, which is only checked to be greater than
32, so shifts of 32 are still accepted. A shift of 31 also overflows a
signed integer, leading to undefined behavior.

Use check_shl_overflow() to compute the RQ WQE size and reject any
invalid values.

## Which versions are affected by CVE-2026-74297?


## How do I fix CVE-2026-74297?

Apply the vendor's patch.

## Is CVE-2026-74297 being exploited?

There is no known exploitation of CVE-2026-74297 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74297 and fix it if it is affected.

What it is: CVE-2026-74297 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-2026-74297 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-2026-74297/ (Markdown: https://insights.sbomify.com/CVE-2026-74297/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74297
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74297
- OSV: https://osv.dev/vulnerability/CVE-2026-74297

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74297/
Summaries are generated and may contain mistakes; the official description above is the record.