CVE-2026-74743Network attack vectorHinoki check available

Kernel memory corruption via omitted packet headroom

Published Aug 26, 2026 · Updated Aug 27, 2026

Buffer underwrite in affected Linux macvlan kernels allows remote attackers to corrupt memory via traffic to a configured interface. macvlan_init leaves needed_headroom and needed_tailroom at zero instead of inheriting them from the lower device, so header operations can underflow an skb and access freed slab memory. Reachability requires macvlan over a device needing extra header or trailer space; ordinary TCP, UDP, or ICMP traffic can then crash the host kernel.

CVSS severity9.8
Critical
EPSS probability0.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Buffer underwrite in affected Linux macvlan kernels allows remote attackers to corrupt memory via traffic to a configured interface. macvlan_init leaves needed_headroom and needed_tailroom at zero instead of inheriting them from the lower device, so header operations can underflow an skb and access freed slab memory. Reachability requires macvlan over a device needing extra header or trailer space; ordinary TCP, UDP, or ICMP traffic can then crash the host kernel.

The record

CVE
CVE-2026-74743
Published
Aug 26, 2026
Updated
Aug 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-124, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 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=2.6.23
  2. Affected versionversion=b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 <28afc87bd8da0b3348bbbd834c8a89e83712cf5e
  3. Affected versionversion=b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 <8cd90e850e434577bf6774778657d26d6995e53f
  4. Affected versionversion=b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 <8f6a05dbac05725e0786701eb04778c5bdbe4eaa
  5. Affected versionversion=b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 <96fa90b74385b7f2b0d97251dd43d5ee6ca44668
  6. Affected versionversion=b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 <bc9a00fb78e32bccc39d763bfd13a450705bac5d
  7. Affected versionversion=b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 <cef51860becd9700217c81732ca1eb1ea6ed6fe1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.23; version=b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 <28afc87bd8da0b3348bbbd834c8a89e83712cf5e; version=b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 <8cd90e850e434577bf6774778657d26d6995e53f; version=b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 <8f6a05dbac05725e0786701eb04778c5bdbe4eaa; version=b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 <96fa90b74385b7f2b0d97251dd43d5ee6ca44668; version=b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 <bc9a00fb78e32bccc39d763bfd13a450705bac5d; version=b863ceb7ddcea8c55fcf1d7b2ac591d50aa7ed53 <cef51860becd9700217c81732ca1eb1ea6ed6fe1

Published CVSS scores

9.8Linux Kernel CVE TeamCVSS: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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-124Buffer Underwrite ('Buffer Underflow')
T1499.004Application or System Exploitation

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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