Medium · CVSS 6.8CVE-2026-102916

Reachable assertion in illumos bhyve REP string instruction emulation allows guest to panic hostCVE-2026-102916

Answer in brief

CVE-2026-102916 records a Medium severity (CVSS 6.8) vulnerability in Reachable assertion in illumos bhyve REP string instruction emulation allows guest to panic host. The current sources do not mark it as known exploited. The current feed maps OmniOS/OmniOS (generic), illumos/system/bhyve (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 Oct 9, 2026Updated Oct 9, 2026Source checked Oct 9, 2026First seen by HOL Oct 9, 2026Material review Oct 9, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.8
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 6.8. 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 OmniOS/OmniOS (generic), illumos/system/bhyve (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
OmniOS/OmniOSgeneric	>=any <r151054 \|\| >=r151058 <r151058w \|\| >=r151056 <r151056aw \|\| >=r151054 <r151054bw	r151058w, r151056aw, r151054bw
illumos/system/bhyvegeneric	>=e0c0d44e917080841514d0dd031a696c74e8c435 <696ecf8debceed9dc33937d8c8e111e4aeebfdae	696ecf8debceed9dc33937d8c8e111e4aeebfdae

Recommended response

Check inventory. Check lockfiles and deployed manifests for OmniOS/OmniOS, illumos/system/bhyve.
Review the reported fix. Source-reported solution: Update your illumos distribution to one that includes the fix for this issue.

Evidence timeline and material changes

Published upstream
Oct 9, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 9, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 9, 2026

Sources and claim methodology

Upstream source description

A reachable assertion in the illumos bhyve instruction emulator allows a guest to panic the host. When emulating a REP-prefixed MOVS or STOS instruction that accesses guest MMIO, vie_emulate_movs() and vie_emulate_stos() in usr/src/uts/intel/io/vmm/vmm_instruction_emul.c do not clear the VIES_REPEAT status flag on the final iteration. For MMIO regions emulated in the kernel (the local APIC, I/O APIC and HPET), the stale flag causes a VERIFY assertion in vie_advance_pc() to fail, and the host panics. A privileged user within a guest VM can issue a REP MOVS or REP STOS instruction against the local APIC page to cause a denial of service of the host and every other guest running on it. The flaw has existed since 2020 (illumos-gate commit e0c0d44e), and affects any illumos distribution prior to illumos-gate commit 696ecf8d.

Quoted source text, attributed separately from HOL analysis.