SB2026052003 - Integer underflow in Linux kernel crypto mpi
Published: May 20, 2026
Security Bulletin ID
SB2026052003
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Integer underflow (CVE-ID: CVE-2026-43492)
CWE-ID: CWE-191 - Integer underflow
CVSSv4: 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
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.
Remediation
Install update from vendor's website.
References
- 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