Use-after-free in Linux kernel - CVE-2026-31589

Vulnerability identifier: #VU127808

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-31589

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to use-after-free in folio_unmap_invalidate() when accessing mapping->a_ops after the folio has been removed from the mapping and the mapping can be removed. A local user can trigger the vulnerable code path to cause a denial of service.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-hwe-6.17 (Ubuntu package)
linux-gcp-6.17 (Ubuntu package)
linux-oracle-6.17 (Ubuntu package)
linux-azure-6.17 (Ubuntu package)
linux-oem-6.17 (Ubuntu package)
linux-nvidia-6.17 (Ubuntu package)
linux-realtime (Ubuntu package)
linux-gcp (Ubuntu package)
linux-aws (Ubuntu package)
linux-oracle (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure (Ubuntu package)
linux-realtime-6.17 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-ibm (Ubuntu package)
linux-azure-fde (Ubuntu package)

Install security update from vendor's repository.

linux (Ubuntu package) - update to 7.0.0-27.27
linux-hwe-6.17 (Ubuntu package) - update to 6.17.0-42.42
linux-gcp-6.17 (Ubuntu package) - update to 6.17.0-1022.25
linux-oracle-6.17 (Ubuntu package) - update to 6.17.0-1020.20
linux-azure-6.17 (Ubuntu package) - update to 6.17.0-1022.22
linux-oem-6.17 (Ubuntu package) - update to 6.17.0-1032.32
linux-nvidia-6.17 (Ubuntu package) - update to 6.17.0-1031.31
linux-realtime (Ubuntu package) - update to 7.0.0-27.27.1
linux-gcp (Ubuntu package) - update to 7.0.0-1007.7
linux-aws (Ubuntu package) - update to 7.0.0-1008.8
linux-oracle (Ubuntu package) - update to 7.0.0-1007.7
linux-raspi (Ubuntu package) - update to 7.0.0-1014.14
linux-azure (Ubuntu package) - update to 7.0.0-1010.10
linux-realtime-6.17 (Ubuntu package) - update to 6.17.0-1019.22
linux-nvidia (Ubuntu package) - update to 7.0.0-1013.13
linux-ibm (Ubuntu package) - update to 7.0.0-1009.9
linux-azure-fde (Ubuntu package) - update to 7.0.0-1009.9

• https://git.kernel.org/stable/c/b667df39d98a7a24be7c2a40ff0863dac1ad2cd7
• https://git.kernel.org/stable/c/c330e65ea59c4805d6ab6757c4ddfe8c63acef31

• Use-after-free in Linux kernel mm
• Ubuntu update for linux
• Ubuntu update for linux-raspi
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-azure
• Ubuntu update for linux-azure-6.17
• Ubuntu update for linux-oracle-6.17
• Ubuntu update for linux-nvidia-6.17