CVE Catalog

CVE-2026-89765

Low risk· EPSS 8%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.19%

8th percentile - higher than 8% of all known CVEs

Summary

In the Linux kernel on native sparc64, struct __kernel_old_timeval contains a four-byte hole after tv_usec because tv_sec is 64-bit while __kernel_suseconds_t is 32-bit. put_itimerval() fills only the named fields in a stack-allocated __kernel_old_itimerval and copies the entire object to userspace, so getitimer() can expose the two padding holes. The fix zero-initializes the aggregate before assigning the fields.

Risk Assessment

Leakage of uninitialized kernel stack data to userspace can expose sensitive information (e.g., pointers, memory fragments), aiding bypass of security mitigations. This primarily affects systems on the sparc64 architecture.

Recommendation

Update the Linux kernel to a version containing the fix. On sparc64 systems, prioritize the update due to the direct data leak.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: timers/itimer: Zero-init old itimerval before copy to userspace On native sparc64, struct __kernel_old_timeval contains a four-byte hole after tv_usec because tv_sec is 64-bit while __kernel_suseconds_t is 32-bit. put_itimerval() fills only the named fields in a stack-allocated __kernel_old_itimerval and copies the entire object to userspace, so getitimer() can expose the two padding holes. Zero-initialize the aggregate before assigning the fields so implicit padding is deterministic before it crosses the user/kernel boundary.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS