CVE-2021-47536
A critical memory corruption flaw exists in the Linux kernel’s SMC link group cleanup routine. The bug can trigger a kernel panic and potentially allow an attacker to crash the system or gain elevated privileges. The issue has been fixed in the kernel source.
An official fix is available, so this entry is kept for 30 days and then removed automatically.
Who is affected
Linux kernel, including version 5.16 and earlier. System administrators and users running affected kernels are at risk.
Real-world impact
An attacker could crash the kernel, causing a denial‑of‑service, or exploit the memory corruption to gain higher privileges on the affected system.
Why this severity
The CVSS score of 9.8 reflects that the flaw requires no authentication or user interaction, has a low attack complexity, and can completely compromise confidentiality, integrity, and availability.
What to do about it
- 011. Update your Linux kernel to a version that includes the SMC list_del fix.
- 022. Reboot the system to load the updated kernel.
NVD-referenced vendor advisory
Timeline
- May 24, 2024 · May 24, 2024PublishedDisclosed and added to the National Vulnerability Database.
- Aug 4, 2026 · 2d agoAdvisory updatedThe NVD record was last revised.
- Aug 5, 2026 · 1d agoOfficial fix availableA vendor patch or mitigation now exists — see the remediation steps above.