# CVE-2026-53333: mm/mincore: handle non-swap entries before !CONFIG_SWAP guard

> A logic error in the Linux kernel's mincore function can cause spurious warnings and incorrect page residency reporting on kernels without swap support but with migration or memory failure features enabled.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 1 Jul 2026
- **Updated:** 1 Jul 2026
- **Also known as:** BELL-CVE-2026-53333, DEBIAN-CVE-2026-53333, GHSA-hmwj-3ghp-wjg8, UBUNTU-CVE-2026-53333

## What is CVE-2026-53333?

CVE-2026-53333 is a medium-severity denial of service vulnerability in Linux kernel, published on 1 Jul 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:

mm/mincore: handle non-swap entries before !CONFIG_SWAP guard

mincore_swap() also fields migration/hwpoison entries (and shmem
swapin-error entries), which can exist on !CONFIG_SWAP builds when
CONFIG_MIGRATION or CONFIG_MEMORY_FAILURE is enabled.  The
!IS_ENABLED(CONFIG_SWAP) guard ran before the non-swap-entry early return,
so mincore_pte_range() can spuriously WARN and report these pages
nonresident on !CONFIG_SWAP kernels.

Move the guard below the non-swap-entry check so only true swap entries
trip the WARN, and migration/hwpoison entries take the existing "uptodate
/ non-shmem" path.

## Which versions are affected by CVE-2026-53333?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-53333?

Apply the vendor's patch.

## Is CVE-2026-53333 being exploited?

There is no known exploitation of CVE-2026-53333 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53333 and fix it if it is affected.

What it is: CVE-2026-53333 is a medium-severity denial of service vulnerability in Linux kernel, published on 1 Jul 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-2026-53333 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-53333/ (Markdown: https://insights.sbomify.com/CVE-2026-53333/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53333
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53333
- OSV: https://osv.dev/vulnerability/CVE-2026-53333

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53333/
Summaries are generated and may contain mistakes; the official description above is the record.