Reachable assertion in illumos bhyve REP string instruction emulation allows guest to panic host
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.
CVE-2026-102916
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-102916
illumos-gate
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
OmniOS
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://github.com/illumos/illumos-gate",
"vendor": "illumos",
"modules": [
"kernel",
"bhyve",
"vmm"
],
"product": "illumos-gate",
"versions": [
{
"status": "affected",
"changes": [
{
"at": "696ecf8debceed9dc33937d8c8e111e4aeebfdae",
"status": "unaffected"
}
],
"version": "e0c0d44e917080841514d0dd031a696c74e8c435",
"lessThan": "696ecf8debceed9dc33937d8c8e111e4aeebfdae",
"versionType": "git"
}
],
"platforms": [
"x86"
],
"packageName": "system/bhyve",
"programFiles": [
"usr/src/uts/intel/io/vmm/vmm_instruction_emul.c"
],
"collectionURL": "https://illumos.org",
"defaultStatus": "affected"
},
{
"vendor": "OmniOS",
"product": "OmniOS",
"versions": [
{
"status": "affected",
"version": "any",
"lessThan": "r151054",
"versionType": "custom"
},
{
"status": "affected",
"changes": [
{
"at": "r151058w",
"status": "unaffected"
}
],
"version": "r151058",
"lessThan": "r151058w",
"versionType": "custom"
},
{
"status": "affected",
"changes": [
{
"at": "r151056aw",
"status": "unaffected"
}
],
"version": "r151056",
"lessThan": "r151056aw",
"versionType": "custom"
},
{
"status": "affected",
"changes": [
{
"at": "r151054bw",
"status": "unaffected"
}
],
"version": "r151054",
"lessThan": "r151054bw",
"versionType": "custom"
}
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-102916
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #16511 · Revision 1
- Added to Heist Feed
- Publisher date