{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-102916", "assignerOrgId": "0ca53633-f0b5-4853-ba72-e0a2e62000d0", "state": "PUBLISHED", "assignerShortName": "illumos", "dateReserved": "2026-09-29T18:57:32.373Z", "datePublished": "2026-10-09T14:12:08.832Z", "dateUpdated": "2026-10-09T14:13:38.463Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "0ca53633-f0b5-4853-ba72-e0a2e62000d0", "shortName": "illumos", "dateUpdated": "2026-10-09T14:13:38.463Z"}, "title": "Reachable assertion in illumos bhyve REP string instruction emulation allows guest to panic host", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-617", "description": "CWE-617 Reachable Assertion", "type": "CWE"}]}], "affected": [{"vendor": "illumos", "product": "illumos-gate", "platforms": ["x86"], "collectionURL": "https://illumos.org", "packageName": "system/bhyve", "repo": "https://github.com/illumos/illumos-gate", "modules": ["kernel", "bhyve", "vmm"], "programFiles": ["usr/src/uts/intel/io/vmm/vmm_instruction_emul.c"], "versions": [{"status": "affected", "version": "e0c0d44e917080841514d0dd031a696c74e8c435", "lessThan": "696ecf8debceed9dc33937d8c8e111e4aeebfdae", "changes": [{"at": "696ecf8debceed9dc33937d8c8e111e4aeebfdae", "status": "unaffected"}], "versionType": "git"}], "defaultStatus": "affected"}, {"vendor": "OmniOS", "product": "OmniOS", "versions": [{"status": "affected", "version": "any", "lessThan": "r151054", "versionType": "custom"}, {"status": "affected", "version": "r151058", "lessThan": "r151058w", "changes": [{"at": "r151058w", "status": "unaffected"}], "versionType": "custom"}, {"status": "affected", "version": "r151056", "lessThan": "r151056aw", "changes": [{"at": "r151056aw", "status": "unaffected"}], "versionType": "custom"}, {"status": "affected", "version": "r151054", "lessThan": "r151054bw", "changes": [{"at": "r151054bw", "status": "unaffected"}], "versionType": "custom"}], "defaultStatus": "affected"}], "descriptions": [{"lang": "en", "value": "A reachable assertion in the illumos bhyve instruction emulator allows a guest to panic the host. 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In-kernel emulation of the local APIC, I/O APIC and HPET cannot be disabled on affected systems. Update to an illumos distribution that includes the fix.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "No configuration-level mitigation is available. In-kernel emulation of the local APIC, I/O APIC and HPET cannot be disabled on affected systems. Update to an illumos distribution that includes the fix."}]}], "solutions": [{"lang": "en", "value": "Update your illumos distribution to one that includes the fix for this issue.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "Update your illumos distribution to one that includes the fix for this issue."}]}], "credits": [{"lang": "en", "value": "iximeow", "type": "remediation developer"}], "source": {"discovery": "INTERNAL"}, "x_generator": {"engine": "hand-authored"}}}}

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{"affected": [{"affectedData": [{"collectionURL": "https://illumos.org", "defaultStatus": "affected", "modules": ["kernel", "bhyve", "vmm"], "packageName": "system/bhyve", "platforms": ["x86"], "product": "illumos-gate", "programFiles": ["usr/src/uts/intel/io/vmm/vmm_instruction_emul.c"], "repo": "https://github.com/illumos/illumos-gate", "vendor": "illumos", "versions": [{"changes": [{"at": "696ecf8debceed9dc33937d8c8e111e4aeebfdae", "status": "unaffected"}], "lessThan": "696ecf8debceed9dc33937d8c8e111e4aeebfdae", "status": "affected", "version": "e0c0d44e917080841514d0dd031a696c74e8c435", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "OmniOS", "vendor": "OmniOS", "versions": [{"lessThan": "r151054", "status": "affected", "version": "any", "versionType": "custom"}, {"changes": [{"at": "r151058w", "status": "unaffected"}], "lessThan": "r151058w", "status": "affected", "version": "r151058", "versionType": "custom"}, {"changes": [{"at": "r151056aw", "status": "unaffected"}], "lessThan": "r151056aw", "status": "affected", "version": "r151056", "versionType": "custom"}, {"changes": [{"at": "r151054bw", "status": "unaffected"}], "lessThan": "r151054bw", "status": "affected", "version": "r151054", "versionType": "custom"}]}], "source": "0ca53633-f0b5-4853-ba72-e0a2e62000d0"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-102916", "lastModified": "2026-10-09T15:17:06.560", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "YES", "Recovery": "AUTOMATIC", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "LOCAL", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.8, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "PROOF_OF_CONCEPT", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "CONCENTRATED", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:C/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "0ca53633-f0b5-4853-ba72-e0a2e62000d0", "type": "Secondary"}]}, "published": "2026-10-09T15:17:06.560", "references": [{"source": "0ca53633-f0b5-4853-ba72-e0a2e62000d0", "url": "https://github.com/illumos/illumos-gate/commit/696ecf8debceed9dc33937d8c8e111e4aeebfdae"}, {"source": "0ca53633-f0b5-4853-ba72-e0a2e62000d0", "url": "https://illumos.org/issues/18491"}, {"source": "0ca53633-f0b5-4853-ba72-e0a2e62000d0", "url": "https://illumos.topicbox.com/groups/developer/T697a32b688807e56/cve-2026-102916-18491-bhyve-rep-prefix-instr-emulation-fumbles-flags"}], "sourceIdentifier": "0ca53633-f0b5-4853-ba72-e0a2e62000d0", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-617"}], "source": "0ca53633-f0b5-4853-ba72-e0a2e62000d0", "type": "Secondary"}]}

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