CVE-2026-23423 btrfs: free pages on error in btrfs_uring_read_extent()

What is CVE-2026-23423?

CVE-2026-23423 is a medium-severity denial of service vulnerability in Linux kernel, published on 3 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:

btrfs: free pages on error in btrfs_uring_read_extent()

In this function the 'pages' object is never freed in the hopes that it is picked up by btrfs_uring_read_finished() whenever that executes in the future. But that's just the happy path. Along the way previous allocations might have gone wrong, or we might not get -EIOCBQUEUED from btrfs_encoded_read_regular_fill_pages(). In all these cases, we go to a cleanup section that frees all memory allocated by this function without assuming any deferred execution, and this also needs to happen for the 'pages' allocation.

Weakness: CWE-401

Which versions are affected by CVE-2026-23423?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-23423?

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-2026-23423 being exploited?

There is no known exploitation of CVE-2026-23423 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 BELL-CVE-2026-23423, DEBIAN-CVE-2026-23423, GHSA-rc42-xqq7-h58r, UBUNTU-CVE-2026-23423.