CVE-2026-102916

MEDIUMPre-NVD 6.86.8
EchelonGraph scoreLOW confidence

This medium-severity CVE scores 6.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: secondary
Trending — 3 sources updated this week
6.8EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 6.8Exploit: None knownExposed services: Not assessed

An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.

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.

CVSS v3
6.8
EG Score
6.8MEDIUMlow confidence
EG Risk
31
EG Risk 31/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity68% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines until it ships, then apply the release.
EPSS PROB
—
EPSS %ILE
—
KEV
Not listed

CISA SSVCTrack at every mission impact level.

An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines until it ships, then apply the release.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

October 9, 2026

Last Modified

October 9, 2026

Advisory Details (3)

Auto-updated Oct 9, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
github_commit

commit 696ecf8debce (illumos/illumos-gate)

Fix landed in illumos/illumos-gate commit 696ecf8debce — awaiting tagged release

https://github.com/illumos/illumos-gate/commit/696ecf8debceed9dc33937d8c8e111e4aeebfdae
generic

Bug #18491: bhyve: rep prefix instr emulation fumbles flags - illumos gate - illumos

https://illumos.org/issues/18491
generic

Topicbox

https://illumos.topicbox.com/groups/developer/T697a32b688807e56/cve-2026-102916-18491-bhyve-rep-prefix-instr-emulation-fumbles-flags

Vendor Advisories for CVE-2026-102916(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 12× in last 7d / 12× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-09 22:22 UTCEG score recompute
  2. 2026-10-09 22:22 UTCGHSA enrichment
  3. 2026-10-09 21:25 UTCEG score recompute
  4. 2026-10-09 21:25 UTCGHSA enrichment
  5. 2026-10-09 17:35 UTCEG score recompute
  6. 2026-10-09 17:35 UTCGHSA enrichment
  7. 2026-10-09 16:54 UTCEG score recompute
  8. 2026-10-09 16:54 UTCGHSA enrichment
  9. 2026-10-09 15:32 UTCEG score recompute
  10. 2026-10-09 15:32 UTCGHSA enrichment
  11. 2026-10-09 14:30 UTCEG score recompute
  12. 2026-10-09 14:28 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(4)

What is CVE-2026-102916?
CVE-2026-102916 is a medium vulnerability published on October 9, 2026. 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, vieemulatemovs() and vieemulatestos() in usr/src/uts/intel/io/vmm/vmminstructionemul.c do not clear the VIESREPEAT…
When was CVE-2026-102916 disclosed?
CVE-2026-102916 was first published on October 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-102916?
CVE-2026-102916 has a CVSS base score of 6.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-102916?
An upstream fix for CVE-2026-102916 has been merged but is not yet in a tagged release. Until it ships, restrict network exposure of the affected system or apply the vendor's mitigation, then update to the release that contains the fix. The vendor advisories EchelonGraph has for CVE-2026-102916 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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