CVE-2026-89917

UNRATEDCVSS · not yet scoredTrending — 3 sources updated this week
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EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No CVSS published and no exploitation signals yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS v2: —Exploit: None knownExposed services: Not assessed

No fix is confirmed yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for the fix.

In the Linux kernel, the following vulnerability has been resolved:

KVM: arm64: Handle VNCR TLB invalidation race with vcpu_put() VNCR unmapping

While VNCR TLB invalidation always occurs under the MMU lock, vcpu_put() doesn't, while it unmaps the VNCR page.

The problem is that the invalidation evaluates vncr_tlb::cpu to decide whether an unmapping needs to take place (cpu != -1) before performing it. On the other hand, this_cpu_reset_vncr_fixmap() unconditionally unmaps if L1_VNCR_MAPPED is set.

These two obviously can race, with a TOCTOU pattern on the TLBI path, and a BUG_ON() on the vcpu_put() path. And the two can end-up calling vncr_fixmap(-1), with extra lethal effects.

Move the reset of vncr_tlb::cpu to -1 to a common function, and make this update atomic so that only a single thread can reset the field and perform the corresponding unmap. The vcpu_put() still need to unconditionally unmap the current VNCR to close another ugly race.

Finally, the assignment of vncr_tlb::cpu is moved to be kept in sync with the actual mapping, similar to L1_VNCR_MAPPED being set.

CVSS v3
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EchelonGraph score
Not yet assessedNo source has published severity data for this CVE yet — no CVSS score from NVD or a CNA, no GitHub advisory, and it is not in CISA KEV. This is not a rating of zero; we cannot assess it yet.
EG Score
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EG Risk
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EPSS PROB
0.2%
EPSS %ILE
9th
KEV
Not listed

Published

September 16, 2026

Last Modified

September 16, 2026

References (3)

Vendor Advisories for CVE-2026-89917(1)

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

Affected Packages

(1 across 1 ecosystem)
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
linux6.12.100-1 ... 7.2~rc7-1~exp1 (178 versions)
  • every version up to 7.2.6-1: fixed in 7.2.6-1
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Data Freshness Timeline

(refreshed 8× in last 7d / 24× 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. 2026-10-04 23:22 UTCEPSS rescore
  2. 2026-10-02 18:57 UTCGHSA enrichment
  3. 2026-10-01 19:51 UTCEPSS rescore
  4. 2026-09-30 15:04 UTCEPSS rescore
  5. 2026-09-29 12:38 UTCEG score recompute
  6. 2026-09-29 12:38 UTCGHSA enrichment
  7. 2026-09-28 13:52 UTCEPSS rescore
  8. 2026-09-28 13:52 UTCEPSS rescore
  9. 2026-09-27 13:49 UTCEPSS rescore
  10. 2026-09-26 15:59 UTCEPSS rescore
  11. 2026-09-26 06:19 UTCGHSA enrichment
  12. 2026-09-24 14:04 UTCEPSS rescore
  13. 2026-09-23 17:54 UTCEPSS rescore
  14. 2026-09-23 00:00 UTCGHSA enrichment
  15. 2026-09-22 16:01 UTCEPSS rescore
  16. 2026-09-21 21:09 UTCEPSS rescore
  17. 2026-09-20 20:16 UTCEPSS rescore
  18. 2026-09-19 17:41 UTCEG score recompute
  19. 2026-09-19 17:41 UTCGHSA enrichment
  20. 2026-09-18 19:28 UTCEPSS rescore
  21. 2026-09-17 19:32 UTCEPSS rescore
  22. 2026-09-16 11:21 UTCNVD update
  23. 2026-09-16 10:39 UTCEG score recompute
  24. 2026-09-16 10:36 UTCMITRE cvelistV5first tracked

Frequently asked(4)

What is CVE-2026-89917?
CVE-2026-89917 is a publicly disclosed vulnerability published on September 16, 2026. In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Handle VNCR TLB invalidation race with vcpu_put() VNCR unmapping While VNCR TLB invalidation always occurs under the MMU lock, vcpu_put() doesn't, while it unmaps the VNCR page. The problem is that the invalidation…
When was CVE-2026-89917 disclosed?
CVE-2026-89917 was first published on September 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-89917 actively exploited?
CVE-2026-89917 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (9th percentile of EPSS-scored CVEs).
How do I remediate CVE-2026-89917?
No fix for CVE-2026-89917 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix. The vendor advisories EchelonGraph has for CVE-2026-89917 are linked in the Vendor Advisories panel on this page.

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