Improper Initialization in Linux kernel - CVE-2026-80873
Published: September 5, 2026
Vulnerability identifier: #VU147042
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-80873
CWE-ID: CWE-665
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a guest L2 hypervisor to observe a stale ESR_EL2 value.
The vulnerability exists due to improper initialization of ESR_EL2 in kvm_inject_el2_exception() when injecting nested SError exceptions. A local user can trigger a nested SError exception to cause a guest L2 hypervisor to observe a stale ESR_EL2 value.
The issue also affects the EASE path in kvm_inject_nested_sea().
Affected software
Linux kernel
How to mitigate CVE-2026-80873
Install security update from vendor's repository.