Integer underflow in Linux kernel - CVE-2026-43492
Published: May 20, 2026
Vulnerability identifier: #VU131910
CSH Severity: Low
CVSS v4.0: 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/E:U/U:Clear
CVE-ID: CVE-2026-43492
CWE-ID: CWE-191
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to integer underflow in mpi_read_raw_from_sgl() when processing a crafted scatterlist during a KEYCTL_PKEY_ENCRYPT system call. A local user can supply an input buffer of zeroes with a larger out_len than in_len to cause a denial of service.
The issue can cause the kernel to spin forever, resulting in soft lockup splats.
How to mitigate CVE-2026-43492
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/26d3a97ad46c7a9226ec04d4bf35bd4998a97d16
- https://git.kernel.org/stable/c/2aa77a18dc7f2670497fe3ee5acbeda0b57659e5
- https://git.kernel.org/stable/c/30e513e755bb381afce6fb57cdc8694136193f22
- https://git.kernel.org/stable/c/8637dfb4c1d8a7026ef681f2477c6de8b71c4003
- https://git.kernel.org/stable/c/8c2f1288250a90a4b5cabed5d888d7e3aeed4035