CVE-2026-68299Network attack vector

Remote kernel crash via Geneve header misclassification

Published Aug 10, 2026 · Updated Aug 10, 2026

Reachable assertion in the Linux kernel allows remote attackers to crash vmxnet3 guests via crafted Geneve-encapsulated traffic. vmxnet3_get_hdr_len() treats completion flags derived from the inner packet as outer-header metadata without skipping the Geneve encapsulation, so outer UDP or differing IP versions fail BUG_ON checks. A remote host must deliver oversized Geneve TCP traffic to an affected VMware guest using vmxnet3; the reported consequence is a guest-kernel crash without data exposure or modification.

CVSS severity7.5
High
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reachable assertion in the Linux kernel allows remote attackers to crash vmxnet3 guests via crafted Geneve-encapsulated traffic. vmxnet3_get_hdr_len() treats completion flags derived from the inner packet as outer-header metadata without skipping the Geneve encapsulation, so outer UDP or differing IP versions fail BUG_ON checks. A remote host must deliver oversized Geneve TCP traffic to an affected VMware guest using vmxnet3; the reported consequence is a guest-kernel crash without data exposure or modification.

The record

CVE
CVE-2026-68299
Published
Aug 10, 2026
Updated
Aug 10, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-617, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.2
  2. Affected versionversion=45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc <28cb5d8d13b4c1faf3f688f62e5df82fe7b438d8
  3. Affected versionversion=45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc <34a71f5361fc3adb5b7138da78750b0d535a8252
  4. Affected versionversion=45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc <4fdb0f162ccdbe9626863b10003855703253fa29
  5. Affected versionversion=45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc <667b6e52048eaf4dbcf1707ed87ffd44abb9cb38
  6. Affected versionversion=45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc <b28596baf87e25a078789f1c05817c8a3bf71257

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.2; version=45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc <28cb5d8d13b4c1faf3f688f62e5df82fe7b438d8; version=45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc <34a71f5361fc3adb5b7138da78750b0d535a8252; version=45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc <4fdb0f162ccdbe9626863b10003855703253fa29; version=45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc <667b6e52048eaf4dbcf1707ed87ffd44abb9cb38; version=45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc <b28596baf87e25a078789f1c05817c8a3bf71257

Published CVSS scores

7.5Linux Kernel CVE teamCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.0Red HatCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-617Reachable Assertion
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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