CVE-2026-72393

System crash via stale skb shared-info pointer

Published Aug 15, 2026 · Updated Aug 15, 2026

Use-after-free in the fbnic Ethernet driver in Linux allows local users to crash the system through crafted outbound traffic. fbnic_tx_lso caches an skb shared-info pointer before skb_cow_head can reallocate and free the original buffer, then reads through the stale pointer. Reachability requires the fbnic driver and compatible Meta FBNIC hardware, and the demonstrated consequence is a kernel crash.

CVSS severity9.8
Critical
EPSS probability0.58%
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 the fbnic Ethernet driver in Linux allows local users to crash the system through crafted outbound traffic. fbnic_tx_lso caches an skb shared-info pointer before skb_cow_head can reallocate and free the original buffer, then reads through the stale pointer. Reachability requires the fbnic driver and compatible Meta FBNIC hardware, and the demonstrated consequence is a kernel crash.

The record

CVE
CVE-2026-72393
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-825, T1499
Attack vector
local
Privileges
authenticated

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

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=6.15
  2. Affected versionversion=b0b0f52042acb324cd39fbefb2b1ae83af8f8ae1 <21f304c2aae46625e050c28d979f4b9d83faa85e
  3. Affected versionversion=b0b0f52042acb324cd39fbefb2b1ae83af8f8ae1 <62b68b774f06bf52e329f254f0199bc43d350ccf
  4. Affected versionversion=b0b0f52042acb324cd39fbefb2b1ae83af8f8ae1 <83df3e2594cd78aa40b1246a19879abb4891945b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.15; version=b0b0f52042acb324cd39fbefb2b1ae83af8f8ae1 <21f304c2aae46625e050c28d979f4b9d83faa85e; version=b0b0f52042acb324cd39fbefb2b1ae83af8f8ae1 <62b68b774f06bf52e329f254f0199bc43d350ccf; version=b0b0f52042acb324cd39fbefb2b1ae83af8f8ae1 <83df3e2594cd78aa40b1246a19879abb4891945b

Published CVSS scores

5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
9.8Linux CNA via CVE.orgCVSS:3.1/AV:N/AC:L/PR:N/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-825Expired Pointer Dereference
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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