# CVE-2026-64146: erofs: fix metabuf leak in inode xattr initialization

> A memory leak in the Linux kernel's EROFS filesystem can lead to resource exhaustion and denial of service.

- **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:** 19 Jul 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-92826, BELL-CVE-2026-64146, DEBIAN-CVE-2026-64146, GHSA-556c-3r39-wvfx, UBUNTU-CVE-2026-64146

## What is CVE-2026-64146?

CVE-2026-64146 is a medium-severity memory corruption vulnerability in Linux kernel, published on 19 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:

erofs: fix metabuf leak in inode xattr initialization

commit bb88e8da0025 ("erofs: use meta buffers for xattr operations")
converted xattr operations to use on-stack erofs_buf instances.
erofs_init_inode_xattrs() uses such a metabuf while reading the inline
xattr header and shared xattr id array.

Some error paths after erofs_read_metabuf() leave through out_unlock
without dropping the metabuf, so the folio reference can leak.

Consolidate the cleanup at out_unlock. erofs_put_metabuf() is a
no-op if no folio has been acquired, and this keeps all paths after
taking EROFS_I_BL_XATTR_BIT covered by a single cleanup site.

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2026-64146?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64146?

Apply the vendor's patch.

## Is CVE-2026-64146 being exploited?

There is no known exploitation of CVE-2026-64146 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-2026-64146 and fix it if it is affected.

What it is: CVE-2026-64146 is a medium-severity memory corruption vulnerability in Linux kernel, published on 19 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-2026-64146 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-2026-64146/ (Markdown: https://insights.sbomify.com/CVE-2026-64146/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64146
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64146
- OSV: https://osv.dev/vulnerability/CVE-2026-64146

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64146/
Summaries are generated and may contain mistakes; the official description above is the record.