CVE-2026-63938
KVM: SEV: Check PSC request indices against the actual size of the buffer
Description
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.
INFO
Published Date :
July 19, 2026, 4:17 p.m.
Last Modified :
July 27, 2026, 5:44 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel to the latest version.
- Ensure guest provided pointers are validated.
- Apply the specific KVM SEV patch.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-63938.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-63938 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-63938
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-63938 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-63938 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 20, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 19, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '9b54e248d2644be71cb394eb85f31ad99e023a05', 'lessThan': '5198f70c09a5f6e9e5f5a0a2c6b388f24294b176', 'versionType': 'git'}, {'status': 'affected', 'version': '9b54e248d2644be71cb394eb85f31ad99e023a05', 'lessThan': '75c8d1d7291268b479794fba5808971dc2f5eaf3', 'versionType': 'git'}, {'status': 'affected', 'version': '9b54e248d2644be71cb394eb85f31ad99e023a05', 'lessThan': '505a3b94535583e4265360e2621734e355ef263d', 'versionType': 'git'}, {'status': 'affected', 'version': '9b54e248d2644be71cb394eb85f31ad99e023a05', 'lessThan': '121d88de56bc5c0ba0ce2f6381af67f948a7e7c1', 'versionType': 'git'}], 'programFiles': ['arch/x86/kvm/svm/sev.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.11'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.11', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.93', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.35', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.12', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['arch/x86/kvm/svm/sev.c'], 'defaultStatus': 'affected'}] Added Description 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. Added Reference https://git.kernel.org/stable/c/121d88de56bc5c0ba0ce2f6381af67f948a7e7c1 Added Reference https://git.kernel.org/stable/c/505a3b94535583e4265360e2621734e355ef263d Added Reference https://git.kernel.org/stable/c/5198f70c09a5f6e9e5f5a0a2c6b388f24294b176 Added Reference https://git.kernel.org/stable/c/75c8d1d7291268b479794fba5808971dc2f5eaf3