CVE-2026-68166

UNRATEDCVSS · not yet scoredTrending — Patch released this week
—
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No CVSS published and no exploitation signals yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS v2: —Exploit: None knownExposed: 0

A fix is available — apply it.

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

userfaultfd: prevent registration of special VMAs

Vova Tokarev says:

userfaultfd allows registration on shadow stack VMAs. With userfaultfd access, you can register on the shadow stack, discard a page ... and inject a page with chosen return addresses via UFFDIO_COPY.

Update vma_can_userfault() to reject VM_SHADOW_STACK.

While on it, also reject VM_SPECIAL so that if a driver would implement vm_uffd_ops, it wouldn't be possible to register special VMAs with userfaultfd.

Since VM_SPECIAL includes VM_DONTEXPAND which is set but hugetlb, exclude hugetlb VMAs from the check for VM_SPECIAL.

CVSS v3
—
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
—
EPSS PROB
0%
EPSS %ILE
10%
KEV
Not listed

Published

August 10, 2026

Last Modified

August 23, 2026

References (5)

Vendor Advisories for CVE-2026-68166(5)

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

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatkernel-0:5.14.0-570.141.1.el9_62026-09-16redhat
redhatkernel-0:5.14.0-687.44.1.el9_82026-09-04redhat
redhatkernel-0:6.12.0-211.50.1.el10_22026-09-01redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(2 across 2 ecosystems)
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 6.12.96-1 (33 versions)6.12.105-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (160 versions)7.1.6-1—

Data Freshness Timeline

(refreshed 7× in last 7d / 38× 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. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-17 00:49 UTCVendor advisory
  3. 2026-09-17 00:49 UTCGHSA enrichment
  4. 2026-09-16 14:08 UTCEPSS rescore
  5. 2026-09-16 05:15 UTCEPSS rescore
  6. 2026-09-13 16:24 UTCVendor advisory
  7. 2026-09-13 16:24 UTCGHSA enrichment
  8. 2026-09-11 14:53 UTCEPSS rescore
  9. 2026-09-11 09:37 UTCEPSS rescore
  10. 2026-09-10 17:11 UTCVendor advisory
  11. 2026-09-10 17:11 UTCGHSA enrichment
  12. 2026-09-08 22:01 UTCEPSS rescore
  13. 2026-09-07 17:26 UTCVendor advisory
  14. 2026-09-07 17:26 UTCGHSA enrichment
  15. 2026-09-07 16:01 UTCEPSS rescore
  16. 2026-09-06 13:47 UTCEPSS rescore
  17. 2026-09-05 15:31 UTCEPSS rescore
  18. 2026-09-04 15:59 UTCVendor advisory
  19. 2026-09-04 15:59 UTCGHSA enrichment
  20. 2026-09-04 05:07 UTCEPSS rescore
  21. 2026-09-02 14:12 UTCEPSS rescore
  22. 2026-09-01 16:45 UTCGHSA enrichment
  23. 2026-09-01 13:54 UTCEPSS rescore
  24. 2026-09-01 04:40 UTCEPSS rescore
  25. 2026-08-30 19:17 UTCEPSS rescore
Show 31 more
  1. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 15:30 UTCGHSA enrichment
  3. 2026-08-28 21:42 UTCEPSS rescore
  4. 2026-08-26 14:47 UTCEPSS rescore
  5. 2026-08-26 12:41 UTCGHSA enrichment
  6. 2026-08-25 13:49 UTCEPSS rescore
  7. 2026-08-23 13:21 UTCGHSA enrichment
  8. 2026-08-23 13:19 UTCNVD update
  9. 2026-08-23 13:08 UTCGHSA enrichment
  10. 2026-08-23 13:05 UTCMITRE cvelistV5
  11. 2026-08-23 04:05 UTCGHSA enrichment
  12. 2026-08-21 23:49 UTCEPSS rescore
  13. 2026-08-20 22:56 UTCEPSS rescore
  14. 2026-08-20 04:53 UTCGHSA enrichment
  15. 2026-08-19 17:04 UTCEPSS rescore
  16. 2026-08-18 13:48 UTCEPSS rescore
  17. 2026-08-17 13:47 UTCEPSS rescore
  18. 2026-08-17 05:40 UTCGHSA enrichment
  19. 2026-08-17 05:26 UTCNVD update
  20. 2026-08-17 05:10 UTCGHSA enrichment
  21. 2026-08-17 05:05 UTCMITRE cvelistV5
  22. 2026-08-16 14:56 UTCEPSS rescore
  23. 2026-08-16 11:52 UTCGHSA enrichment
  24. 2026-08-15 01:30 UTCEPSS rescore
  25. 2026-08-13 22:00 UTCEPSS rescore
  26. 2026-08-13 12:40 UTCEG score recompute
  27. 2026-08-13 12:40 UTCGHSA enrichment
  28. 2026-08-12 13:51 UTCEPSS rescore
  29. 2026-08-10 13:24 UTCNVD update
  30. 2026-08-10 12:20 UTCEG score recompute
  31. 2026-08-10 12:17 UTCMITRE cvelistV5first tracked

Frequently asked(4)

What is CVE-2026-68166?
CVE-2026-68166 is a publicly disclosed vulnerability published on August 10, 2026. In the Linux kernel, the following vulnerability has been resolved: userfaultfd: prevent registration of special VMAs Vova Tokarev says: userfaultfd allows registration on shadow stack VMAs. With userfaultfd access, you can register on the shadow stack, discard a page ... and inject a page with…
When was CVE-2026-68166 disclosed?
CVE-2026-68166 was first published in the National Vulnerability Database on August 10, 2026, with the most recent update on August 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-68166 actively exploited?
CVE-2026-68166 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 89.8% of all scored CVEs.
How do I remediate CVE-2026-68166?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-68166, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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