dbcve.org
Linux KernelOperating system · Linux

CVE-2026-53327

MEDIUM · 5.5 CVSS v3.1 Published 2026-07-01
Fix available
A fix is available. Upgrade to 6.1.177 / 6.6.144 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available 7 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In the Linux kernel's debugobjects subsystem, the fill_pool() function calls rtlock_lock() on RT-enabled kernels. rtlock_lock() asserts that current::pi_blocked_on is not set, since a task can only block on one lock to avoid corrupting the priority inheritance chain. When debugobjects triggers fill_pool() while a task is already blocked on a lock (pi_blocked_on set), the assertion fails, causing a kernel panic or crash.

MitigationThis is a kernel bug requiring a code fix that expands the conditional in fill_pool() to check current::pi_blocked_on before calling rtlock_lock(). No user-configurable mitigation exists; the fix must be applied at the kernel level.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 5.15, < 6.1.177>= 6.2, < 6.6.144>= 6.7, < 6.12.95>= 6.13, < 6.18.37>= 6.19, < 7.0.13= 7.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check kernel version
    Run `uname -r` to obtain the running kernel version. Compare this version against the affected ranges: >= 5.15 and < 6.1.177; >= 6.2 and < 6.6.144; >= 6.7 and < 6.12.95; >= 6.13 and < 6.18.37; >= 6.19 and < 7.0.13; = 7.1
    Affected if The kernel version falls within any of the listed affected version ranges
  2. Verify RT kernel variant
    Determine if the kernel is a Real-Time (RT) variant. Inspect the output of `uname -r` for 'rt' or 'PREEMPT_RT' in the version string, or check /proc/version, or examine /boot/config-$(uname -r) for CONFIG_PREEMPT_RT if available
    Affected if The system is running an RT-enabled kernel (the version string contains 'rt' or 'PREEMPT_RT' or CONFIG_PREEMPT_RT is set in the kernel config)
  3. Confirm debugobjects availability
    The debugobjects subsystem is built into the kernel by default. Verify it exists by checking if /sys/kernel/debug/debug_objects is accessible (requires debugfs mounted at /sys/kernel/debug), or check /boot/config-$(uname -r) for CONFIG_DEBUG_OBJECTS
    Affected if The kernel has CONFIG_DEBUG_OBJECTS enabled and debugfs is mounted, making the debugobjects subsystem accessible

The system is affected only if it is running an RT-enabled kernel with a version that falls within the affected ranges AND has the debugobjects subsystem available (which is the default configuration).

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 6.1.177 / 6.6.144 / 6.12.95 or later
Fixed in 6.1.1776.6.1446.12.95
Vendor patch git.kernel.org →
Interim mitigation

This is a kernel bug requiring a code fix that expands the conditional in fill_pool() to check current::pi_blocked_on before calling rtlock_lock(). No user-configurable mitigation exists; the fix must be applied at the kernel level.

Recommended fix High confidence

6.1.177 (for 5.15-6.1.x branch), 6.6.144 (for 6.2-6.6.x branch), 6.12.95 (for 6.7-6.12.x branch), or 6.18.37 (for 6.13+ branch)

  1. 1. Identify the current running kernel version using 'uname -r'
  2. 2. Determine which kernel branch your current version belongs to (5.15-6.1, 6.2-6.6, 6.7-6.12, or 6.13+)
  3. 3. Upgrade the kernel to the appropriate fixed version for your branch: For 5.15/6.1.x branch, upgrade to >= 6.1.177; For 6.2-6.6.x branch, upgrade to >= 6.6.144; For 6.7-6.12.x branch, upgrade to >= 6.12.95; For 6.13+ branch, upgrade to >= 6.18.37
  4. 4. Use your distribution's package manager to install the updated kernel (e.g., 'apt update && apt upgrade' on Debian/Ubuntu, 'yum update' on RHEL/CentOS, or 'pacman -Syu' on Arch)
  5. 5. Reboot the system to load the fixed kernel
  6. 6. Verify the new kernel version is running with 'uname -r'

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA2.0 h
8.0 hours of engineering $1,390
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,224.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-53327 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-53327 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data