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CVE-2026-74749

In the Linux kernel, the following vulnerability has been resolved: rseq: Prevent hard lockup on granted time slice extension __exit_to_user_mode_loop() invokes rseq_grant_timeslice_extension() w…

Published Aug 26, 2026EPSS 0.20%

Overview

CVE-2026-74749 is a known-severity vulnerability. It was published on August 26, 2026.

Technical description

In the Linux kernel, the following vulnerability has been resolved:

rseq: Prevent hard lockup on granted time slice extension

__exit_to_user_mode_loop() invokes rseq_grant_timeslice_extension() with

interrupts enabled. If the extension is granted it invokes

hrtimer_rearm_deferred_tif() to ensure that a pending deferred hrtimer

rearm is handled before exiting to user space.

Though this invokes __hrtimer_rearm_deferred() which expects to be invoked

with interrupts disabled as it takes hrtimer_cpu_base::lock with

raw_spin_lock(). That's a livelock waiting to happen and caught by lockdep:

WARNING: ./include/linux/hrtimer_rearm.h:17 at irqentry_exit, CPU#1: slice_test

WARNING: inconsistent lock state

inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.

Prevent this by disabling interrupts around the invocation of

hrtimer_rearm_deferred_tif() in rseq_grant_timeslice_extension().

[ tglx: Massaged change log ]

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Frequently asked questions

What is CVE-2026-74749?

CVE-2026-74749 is a known-severity vulnerability. It was published on August 26, 2026.

How severe is CVE-2026-74749?

CVSS score information is not yet available for this vulnerability. Check back as the CVE record is updated by NVD analysts.

How do I fix or remediate CVE-2026-74749?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2026-74749?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-74749 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.