Linux Kernel up to 6.12.94/6.18.34/7.0.11 KVM privilege escalation

| CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
|---|---|---|
| 9.5 | $0-$5k | 2.88 |
Summary
A vulnerability marked as very critical has been reported in Linux Kernel up to 6.12.94/6.18.34/7.0.11. This issue affects some unknown processing of the component KVM. This manipulation causes Remote Privilege Escalation. This vulnerability is handled as CVE-2026-63940. The attack can be initiated remotely. There is not any exploit available.
Details
A vulnerability has been found in Linux Kernel up to 6.12.94/6.18.34/7.0.11 and classified as very critical. Affected by this vulnerability is an unknown code of the component KVM. The manipulation with an unknown input leads to a remote privilege escalation vulnerability. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:
In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Ignore Port I/O requests of length '0' Explicitly ignore Port I/O requests of length '0' (or count '0'), so that setting up the software scratch area (and other code) doesn't have to worry about underflowing the length, and to allow for WARNing on trying to configure the scratch area with len==0.
The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2026-63940 since 07/19/2026. The exploitation appears to be easy. The attack can be launched remotely. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/19/2026).
Upgrading to version 6.12.95, 6.18.35 or 7.0.12 eliminates this vulnerability.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Product
Type
Vendor
Name
Version
- 6.12.0
- 6.12.1
- 6.12.2
- 6.12.3
- 6.12.4
- 6.12.5
- 6.12.6
- 6.12.7
- 6.12.8
- 6.12.9
- 6.12.10
- 6.12.11
- 6.12.12
- 6.12.13
- 6.12.14
- 6.12.15
- 6.12.16
- 6.12.17
- 6.12.18
- 6.12.19
- 6.12.20
- 6.12.21
- 6.12.22
- 6.12.23
- 6.12.24
- 6.12.25
- 6.12.26
- 6.12.27
- 6.12.28
- 6.12.29
- 6.12.30
- 6.12.31
- 6.12.32
- 6.12.33
- 6.12.34
- 6.12.35
- 6.12.36
- 6.12.37
- 6.12.38
- 6.12.39
- 6.12.40
- 6.12.41
- 6.12.42
- 6.12.43
- 6.12.44
- 6.12.45
- 6.12.46
- 6.12.47
- 6.12.48
- 6.12.49
- 6.12.50
- 6.12.51
- 6.12.52
- 6.12.53
- 6.12.54
- 6.12.55
- 6.12.56
- 6.12.57
- 6.12.58
- 6.12.59
- 6.12.60
- 6.12.61
- 6.12.62
- 6.12.63
- 6.12.64
- 6.12.65
- 6.12.66
- 6.12.67
- 6.12.68
- 6.12.69
- 6.12.70
- 6.12.71
- 6.12.72
- 6.12.73
- 6.12.74
- 6.12.75
- 6.12.76
- 6.12.77
- 6.12.78
- 6.12.79
- 6.12.80
- 6.12.81
- 6.12.82
- 6.12.83
- 6.12.84
- 6.12.85
- 6.12.86
- 6.12.87
- 6.12.88
- 6.12.89
- 6.12.90
- 6.12.91
- 6.12.92
- 6.12.93
- 6.12.94
- 6.18.0
- 6.18.1
- 6.18.2
- 6.18.3
- 6.18.4
- 6.18.5
- 6.18.6
- 6.18.7
- 6.18.8
- 6.18.9
- 6.18.10
- 6.18.11
- 6.18.12
- 6.18.13
- 6.18.14
- 6.18.15
- 6.18.16
- 6.18.17
- 6.18.18
- 6.18.19
- 6.18.20
- 6.18.21
- 6.18.22
- 6.18.23
- 6.18.24
- 6.18.25
- 6.18.26
- 6.18.27
- 6.18.28
- 6.18.29
- 6.18.30
- 6.18.31
- 6.18.32
- 6.18.33
- 6.18.34
- 7.0.0
- 7.0.1
- 7.0.2
- 7.0.3
- 7.0.4
- 7.0.5
- 7.0.6
- 7.0.7
- 7.0.8
- 7.0.9
- 7.0.10
- 7.0.11
License
Website
- Vendor: https://www.kernel.org/
CPE 2.3
CPE 2.2
CVSSv4
VulDB Vector: 🔒VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 9.9VulDB Meta Temp Score: 9.5
VulDB Base Score: 9.9
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍
CVSSv2
| AV | AC | Au | C | I | A |
|---|---|---|---|---|---|
| 💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
| 💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
| 💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
| Vector | Complexity | Authentication | Confidentiality | Integrity | Availability |
|---|---|---|---|---|---|
| Unlock | Unlock | Unlock | Unlock | Unlock | Unlock |
| Unlock | Unlock | Unlock | Unlock | Unlock | Unlock |
| Unlock | Unlock | Unlock | Unlock | Unlock | Unlock |
VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍
Exploiting
Class: Privilege escalationCWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒
Physical: No
Local: No
Remote: Yes
Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒
| 0-Day | Unlock | Unlock | Unlock | Unlock |
|---|---|---|---|---|
| Today | Unlock | Unlock | Unlock | Unlock |
Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: no mitigation knownStatus: 🔍
0-Day Time: 🔒
Upgrade: Kernel 6.12.95/6.18.35/7.0.12
Timeline
07/19/2026 Advisory disclosed07/19/2026 CVE reserved
07/19/2026 VulDB entry created
07/19/2026 VulDB entry last update
Sources
Vendor: kernel.orgAdvisory: git.kernel.org
Status: Confirmed
CVE: CVE-2026-63940 (🔒)
GCVE (CVE): GCVE-0-2026-63940
GCVE (VulDB): GCVE-100-380461
Entry
Created: 07/19/2026 20:41Changes: 07/19/2026 20:41 (53)
Complete: 🔍
Cache ID: 216::103
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
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