CVE-2026-80850Hinoki check available

Kernel crash via TCP-AO VRF detach race

Published Sep 4, 2026 · Updated Sep 4, 2026

Use-after-free in Linux TCP-AO allows local users to crash the kernel by racing a connection against detachment of a veth from its VRF. tcp_ao_connect_init() directly frees tp->ao_info after a changed L3-master lookup removes the only key, while an RCU receive-path reader can retain and write through the stale pointer. The demonstrated path requires TCP-AO, a veth attached to a VRF, and self-created user and network namespaces; panic_on_warn can turn the reachable warning into a kernel panic.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Use-after-free in Linux TCP-AO allows local users to crash the kernel by racing a connection against detachment of a veth from its VRF. tcp_ao_connect_init() directly frees tp->ao_info after a changed L3-master lookup removes the only key, while an RCU receive-path reader can retain and write through the stale pointer. The demonstrated path requires TCP-AO, a veth attached to a VRF, and self-created user and network namespaces; panic_on_warn can turn the reachable warning into a kernel panic.

The record

CVE
CVE-2026-80850
Published
Sep 4, 2026
Updated
Sep 4, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 4, 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?

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  1. Affected versionversion=248411b8cb8974a1e1c8e43123c1e682fbd64969 <284d7fd0eec8774bd6214921fbf525cf907c590e
  2. Affected versionversion=248411b8cb8974a1e1c8e43123c1e682fbd64969 <594ba77210a1f065832211851a2d7e14d11fcbdb
  3. Affected versionversion=248411b8cb8974a1e1c8e43123c1e682fbd64969 <70051a57786d5b23f059fbaf5c8241eca14d42ed
  4. Affected versionversion=248411b8cb8974a1e1c8e43123c1e682fbd64969 <d17e88b6b60ff4ef64e0dd1444f935cb13dee1cd
  5. Affected versionversion=248411b8cb8974a1e1c8e43123c1e682fbd64969 <ea30dc5267e367b8a5e1e06cc074f813bcbf18b2
  6. Affected versionversion=6.7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=248411b8cb8974a1e1c8e43123c1e682fbd64969 <284d7fd0eec8774bd6214921fbf525cf907c590e; version=248411b8cb8974a1e1c8e43123c1e682fbd64969 <594ba77210a1f065832211851a2d7e14d11fcbdb; version=248411b8cb8974a1e1c8e43123c1e682fbd64969 <70051a57786d5b23f059fbaf5c8241eca14d42ed; version=248411b8cb8974a1e1c8e43123c1e682fbd64969 <d17e88b6b60ff4ef64e0dd1444f935cb13dee1cd; version=248411b8cb8974a1e1c8e43123c1e682fbd64969 <ea30dc5267e367b8a5e1e06cc074f813bcbf18b2; version=6.7

Published CVSS scores

No CVSS assessment is available in this record.

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
PrivilegesUnavailable
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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