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

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$0-$5k2.88

Summaryinfo

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.

Detailsinfo

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.

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Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.95/6.18.35/7.0.12

Timelineinfo

07/19/2026 Advisory disclosed
07/19/2026 +0 days CVE reserved
07/19/2026 +0 days VulDB entry created
07/19/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-63940 (🔒)
GCVE (CVE): GCVE-0-2026-63940
GCVE (VulDB): GCVE-100-380461

Entryinfo

Created: 07/19/2026 20:41
Changes: 07/19/2026 20:41 (53)
Complete: 🔍
Cache ID: 216::103

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