Answer in brief
CVE-2026-63938 records a Critical severity (CVSS 9.3) vulnerability in KVM: SEV: Check PSC request indices against the actual size of the buffer. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 9.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=9b54e248d2644be71cb394eb85f31ad99e023a05 <5198f70c09a5f6e9e5f5a0a2c6b388f24294b176 || >=9b54e248d2644be71cb394eb85f31ad99e023a05 <75c8d1d7291268b479794fba5808971dc2f5eaf3 || >=9b54e248d2644be71cb394eb85f31ad99e023a05 <505a3b94535583e4265360e2621734e355ef263d || >=9b54e248d2644be71cb394eb85f31ad99e023a05 <121d88de56bc5c0ba0ce2f6381af67f948a7e7c1 | 5198f70c09a5f6e9e5f5a0a2c6b388f24294b176, 75c8d1d7291268b479794fba5808971dc2f5eaf3, 505a3b94535583e4265360e2621734e355ef263d, 121d88de56bc5c0ba0ce2f6381af67f948a7e7c1 |
| Linux/Linuxgeneric | 6.11 | Not reported |
Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 27, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 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 maximum size if the guest provided a pointer that isn't exactly at the start of the GHCB shared buffer.
Quoted source text, attributed separately from HOL analysis.