CVE-2026-63937

HIGHPre-NVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-19. the CNA's CVSS baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
Trending — 4 sources updated this week
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.8Exploit: None knownExposed: 0

A fix is available — apply it.

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

KVM: SEV: Use READ_ONCE() when reading entries/indices from PSC buffer

Use READ_ONCE() when reading entries/indices from the guest-accessible Page State Change buffer to defend against TOCTOU bugs.

Don't bother with READ_ONCE()/WRITE_ONCE() for cases where KVM is writing (and not consuming the result!), as the guest isn't supposed to touch the buffer while it's being processed. I.e. using READ_ONCE() is all about protecting against misbehaving guests.

CVSS v3
8.8
EG Score
8.8(medium)
EG Risk
44(Track)
EG Risk 44/100SSVC: Track

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
Severity88% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
6%
KEV
Not listed

Published

July 19, 2026

Last Modified

August 5, 2026

Advisory Details (4)

Auto-updated Jul 20, 2026
No patch confirmed yet.
generic

KVM: SEV: Use READ_ONCE() when reading entries/indices from PSC buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/edbbe88f83b524434974e84808d3093199d67c24
generic

KVM: SEV: Use READ_ONCE() when reading entries/indices from PSC buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/c8cc238093ca6c99267032f6cfe78f59389f3157
generic

KVM: SEV: Use READ_ONCE() when reading entries/indices from PSC buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/bd232801ef1d1fd985d2d4ca3cd1d888303ca86f
generic

KVM: SEV: Use READ_ONCE() when reading entries/indices from PSC buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/b1dfaa6f7a957726a6800135be3659fbe4bbf2a4

Vendor Advisories for CVE-2026-63937(1)

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

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-azure-fde-7.0 (7.0.0-1009.9) @ resolute2026-08-30ubuntu
ubuntulinux-tools-oracle-7.0 (7.0.0-1008.8) @ resolute2026-08-30ubuntu
ubuntulinux-tools-raspi-realtime-7.0 (7.0.0-1015.15) @ resolute2026-08-30ubuntu
ubuntulinux-tools-nvidia-hwe-26.04 (7.0.0-2016.16) @ resolute2026-08-30ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1016.16) @ resolute2026-08-30ubuntu

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
linux6.12.38-1 ... 6.12.94-1~bpo12+1 (27 versions)6.12.94-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.0.9-1~bpo13+1 (138 versions)7.0.12-1—

All Vendor Advisories

(5)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 32× in last 7d / 168× 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.

Showing the most recent 100 of 216 total refreshes for this CVE.

  1. 2026-08-30 02:56 UTCEG score recompute
  2. 2026-08-30 02:56 UTCVendor advisory
  3. 2026-08-30 02:56 UTCGHSA enrichment
  4. 2026-08-28 21:42 UTCEPSS rescore
  5. 2026-08-27 22:42 UTCEG score recompute
  6. 2026-08-27 22:42 UTCVendor advisory
  7. 2026-08-27 22:42 UTCGHSA enrichment
  8. 2026-08-27 14:25 UTCEPSS rescore
  9. 2026-08-27 11:53 UTCVendor advisory
  10. 2026-08-27 11:53 UTCGHSA enrichment
  11. 2026-08-26 22:25 UTCEG score recompute
  12. 2026-08-26 22:25 UTCVendor advisory
  13. 2026-08-26 22:25 UTCGHSA enrichment
  14. 2026-08-26 14:46 UTCEPSS rescore
  15. 2026-08-26 07:25 UTCVendor advisory
  16. 2026-08-26 07:25 UTCGHSA enrichment
  17. 2026-08-25 20:20 UTCEG score recompute
  18. 2026-08-25 20:20 UTCVendor advisory
  19. 2026-08-25 20:19 UTCGHSA enrichment
  20. 2026-08-25 13:49 UTCEPSS rescore
  21. 2026-08-25 09:17 UTCVendor advisory
  22. 2026-08-25 09:17 UTCGHSA enrichment
  23. 2026-08-24 22:27 UTCEG score recompute
  24. 2026-08-24 22:27 UTCVendor advisory
  25. 2026-08-24 22:27 UTCGHSA enrichment
Show 75 more
  1. 2026-08-24 11:38 UTCEG score recompute
  2. 2026-08-24 11:38 UTCVendor advisory
  3. 2026-08-24 11:38 UTCGHSA enrichment
  4. 2026-08-24 00:49 UTCVendor advisory
  5. 2026-08-24 00:49 UTCGHSA enrichment
  6. 2026-08-23 14:00 UTCVendor advisory
  7. 2026-08-23 14:00 UTCGHSA enrichment
  8. 2026-08-23 03:12 UTCEG score recompute
  9. 2026-08-23 03:12 UTCVendor advisory
  10. 2026-08-23 03:12 UTCGHSA enrichment
  11. 2026-08-23 00:19 UTCEPSS rescore
  12. 2026-08-22 16:15 UTCVendor advisory
  13. 2026-08-22 16:15 UTCGHSA enrichment
  14. 2026-08-22 05:15 UTCEG score recompute
  15. 2026-08-22 05:15 UTCVendor advisory
  16. 2026-08-22 05:15 UTCGHSA enrichment
  17. 2026-08-21 23:49 UTCEPSS rescore
  18. 2026-08-21 18:26 UTCVendor advisory
  19. 2026-08-21 18:26 UTCGHSA enrichment
  20. 2026-08-21 07:37 UTCVendor advisory
  21. 2026-08-21 07:37 UTCGHSA enrichment
  22. 2026-08-20 20:48 UTCVendor advisory
  23. 2026-08-20 20:48 UTCGHSA enrichment
  24. 2026-08-20 09:59 UTCVendor advisory
  25. 2026-08-20 09:59 UTCGHSA enrichment
  26. 2026-08-19 23:10 UTCEG score recompute
  27. 2026-08-19 23:10 UTCVendor advisory
  28. 2026-08-19 23:10 UTCGHSA enrichment
  29. 2026-08-19 17:04 UTCEPSS rescore
  30. 2026-08-19 06:51 UTCVendor advisory
  31. 2026-08-19 06:50 UTCGHSA enrichment
  32. 2026-08-18 19:50 UTCEG score recompute
  33. 2026-08-18 19:50 UTCVendor advisory
  34. 2026-08-18 19:50 UTCGHSA enrichment
  35. 2026-08-18 13:48 UTCEPSS rescore
  36. 2026-08-18 04:24 UTCVendor advisory
  37. 2026-08-18 04:24 UTCGHSA enrichment
  38. 2026-08-17 17:35 UTCEG score recompute
  39. 2026-08-17 17:35 UTCGHSA enrichment
  40. 2026-08-17 13:47 UTCEPSS rescore
  41. 2026-08-17 06:43 UTCVendor advisory
  42. 2026-08-17 06:43 UTCGHSA enrichment
  43. 2026-08-16 19:55 UTCEG score recompute
  44. 2026-08-16 19:55 UTCVendor advisory
  45. 2026-08-16 19:55 UTCGHSA enrichment
  46. 2026-08-16 14:56 UTCEPSS rescore
  47. 2026-08-16 09:06 UTCEG score recompute
  48. 2026-08-16 09:06 UTCVendor advisory
  49. 2026-08-16 09:06 UTCGHSA enrichment
  50. 2026-08-15 22:18 UTCVendor advisory
  51. 2026-08-15 22:18 UTCGHSA enrichment
  52. 2026-08-15 11:29 UTCEG score recompute
  53. 2026-08-15 11:29 UTCVendor advisory
  54. 2026-08-15 11:29 UTCGHSA enrichment
  55. 2026-08-15 01:30 UTCEPSS rescore
  56. 2026-08-15 00:39 UTCVendor advisory
  57. 2026-08-15 00:39 UTCGHSA enrichment
  58. 2026-08-14 13:50 UTCVendor advisory
  59. 2026-08-14 13:50 UTCGHSA enrichment
  60. 2026-08-14 03:01 UTCEG score recompute
  61. 2026-08-14 03:01 UTCVendor advisory
  62. 2026-08-14 03:01 UTCGHSA enrichment
  63. 2026-08-13 22:00 UTCEPSS rescore
  64. 2026-08-13 16:12 UTCGHSA enrichment
  65. 2026-08-13 05:23 UTCVendor advisory
  66. 2026-08-13 05:23 UTCGHSA enrichment
  67. 2026-08-12 18:35 UTCEG score recompute
  68. 2026-08-12 18:35 UTCVendor advisory
  69. 2026-08-12 18:35 UTCGHSA enrichment
  70. 2026-08-12 13:51 UTCEPSS rescore
  71. 2026-08-12 07:46 UTCVendor advisory
  72. 2026-08-12 07:46 UTCGHSA enrichment
  73. 2026-08-11 20:57 UTCEG score recompute
  74. 2026-08-11 20:57 UTCVendor advisory
  75. 2026-08-11 20:57 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-63937?
CVE-2026-63937 is a high vulnerability published on July 19, 2026. In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Use READ_ONCE() when reading entries/indices from PSC buffer Use READ_ONCE() when reading entries/indices from the guest-accessible Page State Change buffer to defend against TOCTOU bugs. Don't bother with…
When was CVE-2026-63937 disclosed?
CVE-2026-63937 was first published in the National Vulnerability Database on July 19, 2026, with the most recent update on August 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63937 actively exploited?
CVE-2026-63937 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 93.7% of all scored CVEs.
What is the CVSS score of CVE-2026-63937?
CVE-2026-63937 has a CVSS v4.0 base score of 8.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-63937?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63937, 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.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-63937

Explore →

Is Your Infrastructure Affected by CVE-2026-63937?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs