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9.3
CRITICAL CVSS 3.1
CVE-2026-74310
vhost/net: complete zerocopy ubufs only once
Overview
Description

In the Linux kernel, the following vulnerability has been resolved: vhost/net: complete zerocopy ubufs only once vhost-net initializes one ubuf_info per outstanding zerocopy TX descriptor and hands it to the backend socket. The networking stack may then clone a zerocopy skb before all skb references are released. For example, batman-adv fragmentation reaches skb_split(), which calls skb_zerocopy_clone() and increments the same ubuf_info refcount. vhost_zerocopy_complete() currently treats every ubuf callback as a completed vhost descriptor. It dereferences ubuf->ctx, writes the descriptor completion state, and drops the vhost_net_ubuf_ref even when the callback only releases a cloned skb reference. A backend reset can therefore wait for and free the vhost_net_ubuf_ref while another cloned skb still carries the same ubuf_info. A later completion then dereferences the freed ubufs pointer. KASAN reports the stale completion as: BUG: KASAN: slab-use-after-free in vhost_zerocopy_complete+0x1d7/0x1f0 BUG: KASAN: slab-use-after-free in vhost_zerocopy_complete+0x101/0x1f0 vhost_zerocopy_complete skb_copy_ubufs __dev_forward_skb2 veth_xmit The freed object was allocated from vhost_net_ioctl() while setting the backend and freed through kfree_rcu()/kvfree_rcu_bulk after backend removal, while delayed skb completion still reached vhost_zerocopy_complete(). Honor the generic ubuf_info refcount before touching vhost state, and run the vhost descriptor completion only for the final ubuf reference. This matches the msg_zerocopy_complete() ownership rule for cloned zerocopy skbs.

Details
INFO

Published Date :

Aug. 15, 2026, 6:22 a.m.

Last Modified :

Aug. 17, 2026, 6:19 a.m.

Remotely Exploit :

No

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Impact
Affected Products

The following products are affected by CVE-2026-74310 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
Ensure zerocopy descriptor completions honor reference counts to prevent use-after-free.
  • Apply the Linux kernel patch for vhost/net zerocopy.
  • Verify vhost descriptor completion logic.
  • Ensure reference counts are managed correctly.
  • Complete vhost descriptors only on final reference.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-74310.

URL Resource
https://git.kernel.org/stable/c/321c73baf54d971ce3771fea275c98a247f7ee35
https://git.kernel.org/stable/c/6445b945024f4c7675ae5352b2d5885cb1deea71
https://git.kernel.org/stable/c/8f6898fe80794f2d7c3d38c1158c806e4074a1c4
https://git.kernel.org/stable/c/a9f8a1d2e3ff511eafd4c5462481950c2f4d2b5d
https://git.kernel.org/stable/c/c069437924663539a93a1e5afe90838d9ccee284
https://git.kernel.org/stable/c/ea71f873423fb73e66ad88936d6759ac0ad4aa53
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-74310 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-74310 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-74310 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-74310 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Aug. 17, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
    Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': 'ea71f873423fb73e66ad88936d6759ac0ad4aa53', 'versionType': 'git'}, {'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': '6445b945024f4c7675ae5352b2d5885cb1deea71', 'versionType': 'git'}, {'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': 'a9f8a1d2e3ff511eafd4c5462481950c2f4d2b5d', 'versionType': 'git'}, {'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': '321c73baf54d971ce3771fea275c98a247f7ee35', 'versionType': 'git'}, {'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': 'c069437924663539a93a1e5afe90838d9ccee284', 'versionType': 'git'}, {'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': '8f6898fe80794f2d7c3d38c1158c806e4074a1c4', 'versionType': 'git'}], 'programFiles': ['drivers/vhost/net.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3.1'}, {'status': 'unaffected', 'version': '0', 'lessThan': '3.1', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.97', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.40', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/vhost/net.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': 'ea71f873423fb73e66ad88936d6759ac0ad4aa53', 'versionType': 'git'}, {'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': '6445b945024f4c7675ae5352b2d5885cb1deea71', 'versionType': 'git'}, {'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': 'a9f8a1d2e3ff511eafd4c5462481950c2f4d2b5d', 'versionType': 'git'}, {'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': '321c73baf54d971ce3771fea275c98a247f7ee35', 'versionType': 'git'}, {'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': 'c069437924663539a93a1e5afe90838d9ccee284', 'versionType': 'git'}, {'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': '8f6898fe80794f2d7c3d38c1158c806e4074a1c4', 'versionType': 'git'}], 'programFiles': ['drivers/vhost/net.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3.1'}, {'status': 'unaffected', 'version': '0', 'lessThan': '3.1', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.97', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.40', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/vhost/net.c'], 'defaultStatus': 'affected'}]
  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Aug. 15, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': 'ea71f873423fb73e66ad88936d6759ac0ad4aa53', 'versionType': 'git'}, {'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': '6445b945024f4c7675ae5352b2d5885cb1deea71', 'versionType': 'git'}, {'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': 'a9f8a1d2e3ff511eafd4c5462481950c2f4d2b5d', 'versionType': 'git'}, {'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': '321c73baf54d971ce3771fea275c98a247f7ee35', 'versionType': 'git'}, {'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': 'c069437924663539a93a1e5afe90838d9ccee284', 'versionType': 'git'}, {'status': 'affected', 'version': 'bab632d69ee48a106e779b60cc01adfe80a72807', 'lessThan': '8f6898fe80794f2d7c3d38c1158c806e4074a1c4', 'versionType': 'git'}], 'programFiles': ['drivers/vhost/net.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3.1'}, {'status': 'unaffected', 'version': '0', 'lessThan': '3.1', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.97', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.40', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/vhost/net.c'], 'defaultStatus': 'affected'}]
    Added Description In the Linux kernel, the following vulnerability has been resolved: vhost/net: complete zerocopy ubufs only once vhost-net initializes one ubuf_info per outstanding zerocopy TX descriptor and hands it to the backend socket. The networking stack may then clone a zerocopy skb before all skb references are released. For example, batman-adv fragmentation reaches skb_split(), which calls skb_zerocopy_clone() and increments the same ubuf_info refcount. vhost_zerocopy_complete() currently treats every ubuf callback as a completed vhost descriptor. It dereferences ubuf->ctx, writes the descriptor completion state, and drops the vhost_net_ubuf_ref even when the callback only releases a cloned skb reference. A backend reset can therefore wait for and free the vhost_net_ubuf_ref while another cloned skb still carries the same ubuf_info. A later completion then dereferences the freed ubufs pointer. KASAN reports the stale completion as: BUG: KASAN: slab-use-after-free in vhost_zerocopy_complete+0x1d7/0x1f0 BUG: KASAN: slab-use-after-free in vhost_zerocopy_complete+0x101/0x1f0 vhost_zerocopy_complete skb_copy_ubufs __dev_forward_skb2 veth_xmit The freed object was allocated from vhost_net_ioctl() while setting the backend and freed through kfree_rcu()/kvfree_rcu_bulk after backend removal, while delayed skb completion still reached vhost_zerocopy_complete(). Honor the generic ubuf_info refcount before touching vhost state, and run the vhost descriptor completion only for the final ubuf reference. This matches the msg_zerocopy_complete() ownership rule for cloned zerocopy skbs.
    Added Reference https://git.kernel.org/stable/c/321c73baf54d971ce3771fea275c98a247f7ee35
    Added Reference https://git.kernel.org/stable/c/6445b945024f4c7675ae5352b2d5885cb1deea71
    Added Reference https://git.kernel.org/stable/c/8f6898fe80794f2d7c3d38c1158c806e4074a1c4
    Added Reference https://git.kernel.org/stable/c/a9f8a1d2e3ff511eafd4c5462481950c2f4d2b5d
    Added Reference https://git.kernel.org/stable/c/c069437924663539a93a1e5afe90838d9ccee284
    Added Reference https://git.kernel.org/stable/c/ea71f873423fb73e66ad88936d6759ac0ad4aa53
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 9.3
Attack Vector
Attack Complexity
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Scope
Confidentiality Impact
Integrity Impact
Availability Impact