# CVE-2026-72181: mips: sched: Fix CPUMASK_OFFSTACK memory corruption

> A memory corruption flaw in the Linux kernel MIPS scheduler allows attackers to execute arbitrary code or escalate privileges when CPUMASK_OFFSTACK is enabled.

- **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:** 19 Aug 2026
- **Also known as:** BELL-CVE-2026-72181, DEBIAN-CVE-2026-72181, GHSA-792p-r5w2-5gfr, UBUNTU-CVE-2026-72181

## What is CVE-2026-72181?

CVE-2026-72181 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:

mips: sched: Fix CPUMASK_OFFSTACK memory corruption

This patch addresses a critical memory management flaw. When
CONFIG_CPUMASK_OFFSTACK is enabled, cpumask_var_t is a pointer.
Consequently, sizeof(new_mask) evaluates to the pointer size, causing
copy_from_user() to clobber the mask pointer. Furthermore, the old
logic performed copy_from_user() before allocating the mask.

Fix this by allocating new_mask first. To handle variable-sized user
masks correctly, use cpumask_size() to truncate overly large user masks
or pad undersized masks with zeros before copying the data directly into
the allocated buffer.

## Which versions are affected by CVE-2026-72181?


## How do I fix CVE-2026-72181?

Apply the vendor's patch.

## Is CVE-2026-72181 being exploited?

There is no known exploitation of CVE-2026-72181 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72181 and fix it if it is affected.

What it is: CVE-2026-72181 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-2026-72181 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-2026-72181/ (Markdown: https://insights.sbomify.com/CVE-2026-72181/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72181
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72181
- OSV: https://osv.dev/vulnerability/CVE-2026-72181

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72181/
Summaries are generated and may contain mistakes; the official description above is the record.