CVE-2026-63938

CRITICALPre-NVD 9.39.3—
EchelonGraph scoreMEDIUM confidence

Score 9.3 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-19. the CNA's CVSS baseline 9.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:linux, epss, ghsa
Trending — 4 sources updated this week
9.3EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.3Exploit: None knownExposed: 0

A fix is available — apply it.

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

KVM: SEV: Check PSC request indices against the actual size of the buffer

When processing Page State Change (PSC) requests, validate the PSC buffer against the effective size of the scratch area, which could be less than the maximum size if the guest provided a pointer that isn't exactly at the start of the GHCB shared buffer.

CVSS v3
9.3
EG Score
9.3(medium)
EG Risk
46(Track)
EG Risk 46/100SSVC: 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
Severity93% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
8%
KEV
Not listed

Published

July 19, 2026

Last Modified

August 5, 2026

Advisory Details (4)

Auto-updated Aug 23, 2026
No patch confirmed yet.
generic

KVM: SEV: Check PSC request indices against the actual size of the buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/121d88de56bc5c0ba0ce2f6381af67f948a7e7c1
generic

KVM: SEV: Check PSC request indices against the actual size of the buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/505a3b94535583e4265360e2621734e355ef263d
generic

KVM: SEV: Check PSC request indices against the actual size of the buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/75c8d1d7291268b479794fba5808971dc2f5eaf3
generic

KVM: SEV: Check PSC request indices against the actual size of the buffer - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/5198f70c09a5f6e9e5f5a0a2c6b388f24294b176

Vendor Advisories for CVE-2026-63938(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-oracle-7.0 (7.0.0-1008.8) @ resolute2026-08-30ubuntu
ubuntulinux-tools-azure-fde-7.0 (7.0.0-1009.9) @ resolute2026-08-30ubuntu
ubuntulinux-tools-raspi-realtime-7.0 (7.0.0-1015.15) @ resolute2026-08-30ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1016.16) @ resolute2026-08-30ubuntu
ubuntulinux-tools-nvidia-hwe-26.04 (7.0.0-2016.16) @ 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 61× in last 7d / 345× 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 421 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-63938?
CVE-2026-63938 is a critical vulnerability published on July 19, 2026. In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Check PSC request indices against the actual size of the buffer When processing Page State Change (PSC) requests, validate the PSC buffer against the effective size of the scratch area, which could be less than the…
When was CVE-2026-63938 disclosed?
CVE-2026-63938 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-2026-63938 actively exploited?
CVE-2026-63938 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 91.9% of all scored CVEs.
What is the CVSS score of CVE-2026-63938?
CVE-2026-63938 has a CVSS v4.0 base score of 9.3 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-63938?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63938, 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

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