CVE-2026-74667

Kernel memory disclosure and corruption via unset header

Published Aug 22, 2026 · Updated Aug 25, 2026

Out-of-bounds access in the Linux kernel allows local users to read or corrupt kernel memory through AF_PACKET transmission. packet_parse_headers leaves skb->mac_header unset before the PACKET_QDISC_BYPASS path calls dev_direct_xmit, causing transmit drivers to dereference memory about 64 KiB beyond the buffer head. The path requires CAP_NET_RAW, PACKET_QDISC_BYPASS, and a transmit driver that reads the unset header; user and network namespaces commonly grant the capability.

CVSS severity7.8
High
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

Out-of-bounds access in the Linux kernel allows local users to read or corrupt kernel memory through AF_PACKET transmission. packet_parse_headers leaves skb->mac_header unset before the PACKET_QDISC_BYPASS path calls dev_direct_xmit, causing transmit drivers to dereference memory about 64 KiB beyond the buffer head. The path requires CAP_NET_RAW, PACKET_QDISC_BYPASS, and a transmit driver that reads the unset header; user and network namespaces commonly grant the capability.

The record

CVE
CVE-2026-74667
Published
Aug 22, 2026
Updated
Aug 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 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=5.1
  2. Affected versionversion=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <1e43a1d66615f411d427f9df1f46dd049d9e3681
  3. Affected versionversion=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <2610ed4e86a4590234a9d70518c469751c5af231
  4. Affected versionversion=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d
  5. Affected versionversion=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <4057853a91fb796c4f47c7d1baf1aa085394148e
  6. Affected versionversion=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <971aa7d99242bbf09513e27b7a243f0b29ff23ae
  7. Affected versionversion=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <b47ba8fe6e1d2df8c92048de5afafd059447dc30
  8. Affected versionversion=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <c2707480cfbf19c7619acc9c089d17f20869821f
  9. Affected versionversion=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <fdd4d7d52358a58e351dd9d82530c04eba8ccd7a

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.1; version=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <1e43a1d66615f411d427f9df1f46dd049d9e3681; version=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <2610ed4e86a4590234a9d70518c469751c5af231; version=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d; version=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <4057853a91fb796c4f47c7d1baf1aa085394148e; version=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <971aa7d99242bbf09513e27b7a243f0b29ff23ae; version=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <b47ba8fe6e1d2df8c92048de5afafd059447dc30; version=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <c2707480cfbf19c7619acc9c089d17f20869821f; version=75c65772c3d18447d62d3aca5f91b06c16cc25e4 <fdd4d7d52358a58e351dd9d82530c04eba8ccd7a

Published CVSS scores

7.8Linux kernel CVE teamCVSS:3.1/AV:L/AC:L/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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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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