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

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 include Linux kernel.

How do I fix CVE-2026-46089?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

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 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

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.