October 27, 2026

CVE Watchtower

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CVE-2026-63938NVD

Vulnerability Summary

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.
Severity Level
CRITICAL(9.3)
Published Date
Jul 19, 2026
Last Modified
Oct 27, 2026
Exploitation Status
No confirmed exploitation yet
EPSS Score (30-Day)
0.20%Probability
Root Weakness (CWE)
CWE-125: Out-of-bounds Read ↗
The software reads data past the end, or before the beginning, of the intended buffer.
CVSS v3.1 Base Metrics — Score 9.3 (CRITICAL)
Attack VectorLocal
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

Affected & Patched Versions

Affected Versions
  • Linux Linux Kernel >= 6.11 and < 6.12.93
  • Linux Linux Kernel >= 6.13 and < 6.18.35
  • Linux Linux Kernel >= 6.19 and < 7.0.12
  • Linux Linux Kernel
Patched Versions
  • Linux Linux Kernel 6.12.93
  • Linux Linux Kernel 6.18.35
  • Linux Linux Kernel 7.0.12
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🚫Ad-Free — Uninterrupted experience.
🎁7-Day Free Trial — Try Pro or Team, no card required.
📧Email Delivery — Threat intel straight to your inbox.
♾️Unlimited Vendors — Track your entire stack.
🚨All New CVEs — Be the first to know.
📈EPSS Spike Alerts — Catch rising risk before it peaks.
🎯Custom EPSS/CVSS — Filter noise, focus on risk.
🛡️Exploit Intel — A 2nd confirmed-exploit signal beyond KEV.
🐙GitHub Issues — Auto-tracked, no duplicates.
📬Weekly Digest — One clean summary, not inbox spam.
🏷️Watchlist Groups — Tag alerts by team (Infra/AppSec/SOC).
💬Webhooks — Slack & Teams integration.
🔀Smart Routing — Critical alerts to one channel, rest to another.
🚫Ad-Free — Uninterrupted experience.

External References