What is CVE-2026-31734?

CVE-2026-31734 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 6.18 onward and patched in 6.18.22, 6.19.12 and 7.0. CVE-2026-31734 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-31734?

CVE-2026-31734 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-31734?

Yes, CVE-2026-31734 has been patched. Fixed versions include 6.18.22, 6.19.12 and 7.0. If you are running Linux kernel 6.18 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-31734 actively exploited?

CVE-2026-31734 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-31734

Medium

In the Linux kernel, the following vulnerability has been resolved: sched_ext: Fix is_bpf_migration_disabled() false negative on non-PREEMPT_RCU Since commit 8e4f0b1ebcf2 ("bpf: use rcu_read_lock_dont_migrate() for trampoline.c"), the BPF prolog (__bpf_prog_enter) calls migrate_disable() only when CONFIG_PREEMPT_RCU is enabled, via rcu_read_lock_dont_migrate(). Without CONFIG_PREEMPT_RCU, the prolog never touches migration_disabled, so migration_disabled == 1 always means the task is truly migration-disabled regardless of whether it is the current task. The old unconditional p == current check was a false negative in this case, potentially allowing a migration-disabled task to be dispatched to a remote CPU and triggering scx_error in task_can_run_on_remote_rq(). Only apply the p == current disambiguation when CONFIG_PREEMPT_RCU is enabled, where the ambiguity with the BPF prolog still exists.

Package Linux Kernel

Published 2026-05-01

Last modified 2026-05-07

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

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

Affected versions

Linux kernel versions 6.18 and later are affected. Fixed in 6.18.22, 6.19.12, 7.0 and their respective stable series.

Affected from

≥ 6.18

Fixed in

✓ 6.18.22 6.18.x ✓ 6.19.12 6.19.x ✓ 7.0

References

The following references provide additional information about CVE-2026-31734 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/0c4a59df370bea245695c00aaae6ae75747139bd
Patch
Kernel patch commit
https://git.kernel.org/stable/c/72c43eb2e334febe93018cfb68ae828f55c6e49e
Patch
Kernel patch commit
https://git.kernel.org/stable/c/b4992a9446bb9a639007bfd32bf5c5a7e30199e5
Patch

Details

CVE ID CVE-2026-31734

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-05-01

Modified 2026-05-07

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-31734?

CVE-2026-31734 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 6.18 onward and has been patched in 6.18.22, 6.19.12 and 7.0. CVE-2026-31734 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-31734?

CVE-2026-31734 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2026-31734?

Yes — CVE-2026-31734 has been patched. Fixed versions include 6.18.22, 6.19.12 and 7.0. If you are running Linux kernel 6.18 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-31734 actively exploited?

No — CVE-2026-31734 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.