# CVE-2026-31514: erofs: set fileio bio failed in short read case

> A flaw in the Linux kernel EROFS file-backed mount allows a local attacker to cause a denial of service by triggering a short read condition that incorrectly marks data as valid.

- **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:** 22 Apr 2026
- **Updated:** 23 Oct 2026
- **Also known as:** BELL-CVE-2026-31514, DEBIAN-CVE-2026-31514, GHSA-mgg3-9x9v-hwxx, UBUNTU-CVE-2026-31514

## What is CVE-2026-31514?

CVE-2026-31514 is a medium-severity denial of service vulnerability in Linux kernel, published on 22 Apr 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:

erofs: set fileio bio failed in short read case

For file-backed mount, IO requests are handled by vfs_iocb_iter_read().
However, it can be interrupted by SIGKILL, returning the number of
bytes actually copied. Unused folios in bio are unexpectedly marked
as uptodate.

  vfs_read
    filemap_read
      filemap_get_pages
        filemap_readahead
          erofs_fileio_readahead
            erofs_fileio_rq_submit
              vfs_iocb_iter_read
                filemap_read
                  filemap_get_pages  <= detect signal
              erofs_fileio_ki_complete  <= set all folios uptodate

This patch addresses this by setting short read bio with an error
directly.

## Which versions are affected by CVE-2026-31514?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-31514?

Apply the vendor's patch.

## Is CVE-2026-31514 being exploited?

There is no known exploitation of CVE-2026-31514 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-2026-31514 and fix it if it is affected.

What it is: CVE-2026-31514 is a medium-severity denial of service vulnerability in Linux kernel, published on 22 Apr 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-2026-31514 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-2026-31514/ (Markdown: https://insights.sbomify.com/CVE-2026-31514/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-31514
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31514
- OSV: https://osv.dev/vulnerability/CVE-2026-31514

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-31514/
Summaries are generated and may contain mistakes; the official description above is the record.