CVE-2026-53327 debugobjects: Do not fill_pool() if pi_blocked_on

What is CVE-2026-53327?

CVE-2026-53327 is a medium-severity denial of service vulnerability in Linux kernel, published on 1 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:

debugobjects: Do not fill_pool() if pi_blocked_on

On RT enabled kernels, fill_pool() ends up calling rtlock_lock(), which asserts if current::pi_blocked_on is set, because a task can obviously only block on one lock as otherwise the priority inheritenace chain gets corrupted.

Prevent this by expanding the conditional to take current::pi_blocked_on into account.

Which versions are affected by CVE-2026-53327?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-53327?

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-2026-53327 being exploited?

There is no known exploitation of CVE-2026-53327 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-2026-53327, DEBIAN-CVE-2026-53327, GHSA-6w3p-w4p9-rj2h, ROOT-OS-DEBIAN-12-CVE-2026-53327, ROOT-OS-UBUNTU-2204-CVE-2026-53327, ROOT-OS-UBUNTU-2404-CVE-2026-53327 and 1 more.