Vulnerability in Linux kernel (CVE-2026-64250)
Summary
Vulnerability in Linux kernel (CVE-2026-64250). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: Report dying CPU to RCU in stop_this_cpu()
This is a port of MIPS commit 9f3f3bdc6d9dac1 ("MIPS: smp: report dying
CPU to RCU in stop_this_cpu()"). smp_send_stop() parks all secondary
CPUs in stop_this_cpu(). And the function marks the CPU offline for the
scheduler via set_cpu_online(false) but never informs RCU, so RCU keeps
expecting a quiescent state from CPUs that are now spinning forever with
interrupts disabled.
As long as nothing waits for an RCU grace period after smp_send_stop()
this is harmless, which is why it went unnoticed. However, since commit
91840be8f710370 ("irq_work: Fix use-after-free in irq_work_single() on
PREEMPT_RT"), irq_work_sync() calls synchronize_rcu() on architectures
without an irq_work self-IPI, i.e. where arch_irq_work_has_interrupt()
returns false. Any irq_work_sync() issued in the reboot/shutdown/halt
path after smp_send_stop() then blocks on a grace period that can never
complete, hanging the reboot:
WARNING: CPU: 0 PID: 15 at kernel/irq_work.c:144 irq_work_queue_on
...
rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
rcu: Offline CPU 1 blocking current GP.
rcu: Offline CPU 2 blocking current GP.
rcu: Offline CPU 3 blocking current GP.
This issue needs some hacks to reproduce, and it was not noticed on
LoongArch because arch_irq_work_has_interrupt() usually returns true.
Call rcutree_report_cpu_dead() once interrupts are disabled, mirroring
t…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-64250 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure. CVSS score: 5.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-64250" on the vendor's site.
CVE-2026-64250 (Linux kernel) — CVSS v3 5.5
Attack vector: local / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: Medium (CVSS 5.5/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-64250 linux-lts Fixed in: 6.1.182-r0
- Debian DEBIAN-CVE-2026-64250 linux Fixed in: 6.1.180-1
- Ubuntu UBUNTU-CVE-2026-64250 linux-hwe-edge
References
- advisory nvd.nist.gov
- advisory github.com
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web github.com