timers/itimer: Zero-init old itimerval before copy to userspace (CVE-2026-89765) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89765

timers/itimer: Zero-init old itimerval before copy to userspace

Answer in brief

CVE-2026-89765 records a Unknown severity vulnerability in timers/itimer: Zero-init old itimerval before copy to userspace. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 11, 2026Updated Sep 11, 2026Source checked Sep 11, 2026First seen by HOL Sep 11, 2026Material review Sep 11, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4c66719dd1e4023c5e3f7d050f1bbefec3dfbeb4 \|\| >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2bf5e8f7c9bf4ad3be343a9a6e3e50a34264d25e \|\| >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <00ef529a5402f41eb1d227916437e237450719f9 \|\| >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <18c7d85864e554adc8fad1e8d2e9d2cb6c3911c8 \|\| >=0 <6.12.109 \|\| >=0 <6.18.50 \|\| >=0 <7.2.4	4c66719dd1e4023c5e3f7d050f1bbefec3dfbeb4, 2bf5e8f7c9bf4ad3be343a9a6e3e50a34264d25e, 00ef529a5402f41eb1d227916437e237450719f9, 18c7d85864e554adc8fad1e8d2e9d2cb6c3911c8, 6.12.109, 6.18.50, 7.2.4

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux.
Review the reported fix. Update Linux/Linux to 4c66719dd1e4023c5e3f7d050f1bbefec3dfbeb4 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 11, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.