# CVE-2026-80627: MIPS: mm: Fix out-of-bounds write in maar_res_walk()

> An out-of-bounds write in the MIPS memory management code allows local attackers to potentially execute arbitrary code or escalate privileges.

- **Severity:** Not scored
- **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:** 28 Aug 2026
- **Updated:** 28 Aug 2026
- **Also known as:** BELL-CVE-2026-80627, DEBIAN-CVE-2026-80627, GHSA-52jh-gf9j-c2mq, UBUNTU-CVE-2026-80627

## What is CVE-2026-80627?

CVE-2026-80627 is a memory corruption vulnerability in Linux, published on 28 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: mm: Fix out-of-bounds write in maar_res_walk()

maar_res_walk() uses wi->num_cfg as the index into the fixed-size
wi->cfg array, but checks whether the array is full only after it has
filled the selected entry. If walk_system_ram_range() reports more than
16 memory ranges, the overflow call writes one struct maar_config past
the end of the array before WARN_ON() prevents num_cfg from advancing.

Move the full-array check before taking the array slot and return non-zero
when the scratch array is full, so walk_system_ram_range() terminates the
walk instead of invoking the callback for further ranges.

## Which versions are affected by CVE-2026-80627?


## How do I fix CVE-2026-80627?

Apply the vendor's patch.

## Is CVE-2026-80627 being exploited?

There is no known exploitation of CVE-2026-80627 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80627 and fix it if it is affected.

What it is: CVE-2026-80627 is a memory corruption vulnerability in Linux, published on 28 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-2026-80627 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-2026-80627/ (Markdown: https://insights.sbomify.com/CVE-2026-80627/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80627
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80627
- OSV: https://osv.dev/vulnerability/CVE-2026-80627

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80627/
Summaries are generated and may contain mistakes; the official description above is the record.