Use-after-free in Linux kernel - CVE-2026-90277

Vulnerability identifier: #VU151203

CSH Severity: Low

CVSS v4: 0 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-90277

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to trigger a use-after-free condition.

The vulnerability exists due to a use-after-free in llbitmap_create() when bitmap creation fails while bitmap statistics are being collected. A local user can trigger a failed bitmap creation while a mutex-protected reader accesses bitmap statistics to trigger a use-after-free condition.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

• https://git.kernel.org/stable/c/2116c2f0a0e547615886900e2ed8c529c016499b
• https://git.kernel.org/stable/c/2f0722435ce3a844dbb66b9bb0a18229dcc8739c
• https://git.kernel.org/stable/c/930cc4f1af5a1afcd545a6ba00e38921ff8401e0

• Use-after-free in Linux kernel md driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more