CVE-2026-74310

Guest-to-host compromise via premature ubuf completion

Published Aug 15, 2026 · Updated Aug 15, 2026

Use-after-free in Linux vhost-net allows guest OS users to corrupt host kernel memory through zerocopy transmit completion. The vhost_zerocopy_complete() callback treats each cloned skb ubuf release as a finished descriptor, drops the shared reference, and writes vhost state before the final reference. Exploitation requires experimental_zcopytx, cloned zerocopy transmit buffers, and backend teardown; successful reuse enables host crashes or compromise.

CVSS severity9.3
Critical
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux vhost-net allows guest OS users to corrupt host kernel memory through zerocopy transmit completion. The vhost_zerocopy_complete() callback treats each cloned skb ubuf release as a finished descriptor, drops the shared reference, and writes vhost state before the final reference. Exploitation requires experimental_zcopytx, cloned zerocopy transmit buffers, and backend teardown; successful reuse enables host crashes or compromise.

The record

CVE
CVE-2026-74310
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-825, T1499.004, T1068
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=3.1
  2. Affected versionversion=bab632d69ee48a106e779b60cc01adfe80a72807 <321c73baf54d971ce3771fea275c98a247f7ee35
  3. Affected versionversion=bab632d69ee48a106e779b60cc01adfe80a72807 <6445b945024f4c7675ae5352b2d5885cb1deea71
  4. Affected versionversion=bab632d69ee48a106e779b60cc01adfe80a72807 <8f6898fe80794f2d7c3d38c1158c806e4074a1c4
  5. Affected versionversion=bab632d69ee48a106e779b60cc01adfe80a72807 <a9f8a1d2e3ff511eafd4c5462481950c2f4d2b5d
  6. Affected versionversion=bab632d69ee48a106e779b60cc01adfe80a72807 <c069437924663539a93a1e5afe90838d9ccee284
  7. Affected versionversion=bab632d69ee48a106e779b60cc01adfe80a72807 <ea71f873423fb73e66ad88936d6759ac0ad4aa53

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.1; version=bab632d69ee48a106e779b60cc01adfe80a72807 <321c73baf54d971ce3771fea275c98a247f7ee35; version=bab632d69ee48a106e779b60cc01adfe80a72807 <6445b945024f4c7675ae5352b2d5885cb1deea71; version=bab632d69ee48a106e779b60cc01adfe80a72807 <8f6898fe80794f2d7c3d38c1158c806e4074a1c4; version=bab632d69ee48a106e779b60cc01adfe80a72807 <a9f8a1d2e3ff511eafd4c5462481950c2f4d2b5d; version=bab632d69ee48a106e779b60cc01adfe80a72807 <c069437924663539a93a1e5afe90838d9ccee284; version=bab632d69ee48a106e779b60cc01adfe80a72807 <ea71f873423fb73e66ad88936d6759ac0ad4aa53

Published CVSS scores

6.3Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H
7.0Red HatCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
9.3Linux CNACVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

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

Weakness, pattern, technique

CWE-825Expired Pointer Dereference
T1499.004Application or System Exploitation
T1068Exploitation for Privilege Escalation

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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