Linux Kernel up to 7.2-rc4 vmxnet3 vmxnet3_get_hdr_len input validation

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.2$0-$5k0.53

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 6.6.147/6.12.100/6.18.41/7.1.5/7.2-rc4. Affected by this vulnerability is the function vmxnet3_get_hdr_len of the component vmxnet3. The manipulation results in input validation. This vulnerability is cataloged as CVE-2026-68299. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.6.147/6.12.100/6.18.41/7.1.5/7.2-rc4. Affected is the function vmxnet3_get_hdr_len of the component vmxnet3. The manipulation with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: vmxnet3: fix BUG_ON in vmxnet3_get_hdr_len() for Geneve packets vmxnet3_get_hdr_len() assumes gdesc->rcd.v4/v6/tcp always describe the outer header, but for a Geneve-encapsulated packet the device can set them based on the inner header instead, signalled by the VMXNET3_RCD_HDR_INNER_SHIFT bit in the completion descriptor. Since the function never skips the outer encapsulation, this mismatch triggers: - BUG_ON(hdr.ipv4->protocol != IPPROTO_TCP), because the outer protocol is UDP (Geneve), not TCP. - BUG_ON(hdr.eth->h_proto != ...), when the tunnel's outer and inner IP versions differ (e.g. outer IPv6/inner IPv4 or vice versa). Check VMXNET3_RCD_HDR_INNER_SHIFT up front and bail out, since the function cannot locate the inner header it would need to parse. Also convert the remaining BUG_ON()s in this function to return 0 defensively.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2026-68299 since 07/30/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/10/2026).

Upgrading to version 6.6.148, 6.12.101, 6.18.42, 7.1.6 or 7.2-rc5 eliminates this vulnerability. Applying the patch 667b6e52048eaf4dbcf1707ed87ffd44abb9cb38/28cb5d8d13b4c1faf3f688f62e5df82fe7b438d8/4fdb0f162ccdbe9626863b10003855703253fa29/b28596baf87e25a078789f1c05817c8a3bf71257/34a71f5361fc3adb5b7138da78750b0d535a8252 is able to eliminate this problem.

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Productinfo

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Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.2

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
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: Input validation
CWE: CWE-20
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: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.148/6.12.101/6.18.42/7.1.6/7.2-rc5
Patch: 667b6e52048eaf4dbcf1707ed87ffd44abb9cb38/28cb5d8d13b4c1faf3f688f62e5df82fe7b438d8/4fdb0f162ccdbe9626863b10003855703253fa29/b28596baf87e25a078789f1c05817c8a3bf71257/34a71f5361fc3adb5b7138da78750b0d535a8252

Timelineinfo

07/30/2026 CVE reserved
08/10/2026 +11 days Advisory disclosed
08/10/2026 +0 days VulDB entry created
08/10/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-68299 (🔒)
GCVE (CVE): GCVE-0-2026-68299
GCVE (VulDB): GCVE-100-387684

Entryinfo

Created: 08/10/2026 17:35
Changes: 08/10/2026 17:35 (59)
Complete: 🔍
Cache ID: 216::103

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