# CVE-2026-46089: zram: do not forget to endio for partial discard requests

> A missing endio call in the Linux kernel zram driver causes blkdiscard to hang indefinitely, leading to a 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:** 27 May 2026
- **Updated:** 14 Jun 2026
- **Also known as:** AZL-88779, BELL-CVE-2026-46089, DEBIAN-CVE-2026-46089, GHSA-qc74-hc4j-xrp6, ROOT-OS-UBUNTU-2404-CVE-2026-46089, UBUNTU-CVE-2026-46089

## What is CVE-2026-46089?

CVE-2026-46089 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 May 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:

zram: do not forget to endio for partial discard requests

As reported by Qu Wenruo and Avinesh Kumar, the following

 getconf PAGESIZE
 65536
 blkdiscard -p 4k /dev/zram0

takes literally forever to complete.  zram doesn't support partial
discards and just returns immediately w/o doing any discard work in such
cases.  The problem is that we forget to endio on our way out, so
blkdiscard sleeps forever in submit_bio_wait().  Fix this by jumping to
end_bio label, which does bio_endio().

## Which versions are affected by CVE-2026-46089?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-46089?

Apply the vendor's patch.

## Is CVE-2026-46089 being exploited?

There is no known exploitation of CVE-2026-46089 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-2026-46089 and fix it if it is affected.

What it is: CVE-2026-46089 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 May 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-2026-46089 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-2026-46089/ (Markdown: https://insights.sbomify.com/CVE-2026-46089/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-46089
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-46089
- OSV: https://osv.dev/vulnerability/CVE-2026-46089

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-46089/
Summaries are generated and may contain mistakes; the official description above is the record.