CVE-2026-98251Public exploit

Kernel crash via confirmed conntrack label reallocation

Published Oct 6, 2026 · Updated Oct 6, 2026

A memory-safety flaw in Linux Open vSwitch conntrack allows local users with root access to trigger a kernel panic through label updates. The ovs_ct_get_conn_labels() function adds a missing labels extension to an already confirmed conntrack entry, potentially freeing storage while another CPU reads it. The published reproducer uses BPF and Open vSwitch netlink; its demonstrated panic requires the panic-on-warning setting.

CVSS severityUnavailable
Unscored
EPSS probability0.14%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A memory-safety flaw in Linux Open vSwitch conntrack allows local users with root access to trigger a kernel panic through label updates. The ovs_ct_get_conn_labels() function adds a missing labels extension to an already confirmed conntrack entry, potentially freeing storage while another CPU reads it. The published reproducer uses BPF and Open vSwitch netlink; its demonstrated panic requires the panic-on-warning setting.

The record

CVE
CVE-2026-98251
Published
Oct 6, 2026
Updated
Oct 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Oct 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 6, 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=4.3
  2. Affected versionversion=c2ac667358708d7cce64c78f58af6adf4c1e848b <05eab8dced6bf4d3009a6eeee16ddac99047dc83
  3. Affected versionversion=c2ac667358708d7cce64c78f58af6adf4c1e848b <2e6dd889c325abf23821e1459c3ffef59b7f0009
  4. Affected versionversion=c2ac667358708d7cce64c78f58af6adf4c1e848b <3f118c8217c109fd13ca61caa301d72c483897ef
  5. Affected versionversion=c2ac667358708d7cce64c78f58af6adf4c1e848b <4371d79ea74407fb992c985b1f94391e35bb8289
  6. Affected versionversion=c2ac667358708d7cce64c78f58af6adf4c1e848b <579d87ec1e1e85729a6cb2c25961e58beb78640c
  7. Affected versionversion=c2ac667358708d7cce64c78f58af6adf4c1e848b <7ff688aceada1160331a789385ea146f62fbddf7
  8. Affected versionversion=c2ac667358708d7cce64c78f58af6adf4c1e848b <8c9fcc6c33950d3db551af664d1fd3d998bfee56
  9. Affected versionversion=c2ac667358708d7cce64c78f58af6adf4c1e848b <d16f089bd700f45d720ce989d5495e1dc3be0cf8

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=4.3; version=c2ac667358708d7cce64c78f58af6adf4c1e848b <05eab8dced6bf4d3009a6eeee16ddac99047dc83; version=c2ac667358708d7cce64c78f58af6adf4c1e848b <2e6dd889c325abf23821e1459c3ffef59b7f0009; version=c2ac667358708d7cce64c78f58af6adf4c1e848b <3f118c8217c109fd13ca61caa301d72c483897ef; version=c2ac667358708d7cce64c78f58af6adf4c1e848b <4371d79ea74407fb992c985b1f94391e35bb8289; version=c2ac667358708d7cce64c78f58af6adf4c1e848b <579d87ec1e1e85729a6cb2c25961e58beb78640c; version=c2ac667358708d7cce64c78f58af6adf4c1e848b <7ff688aceada1160331a789385ea146f62fbddf7; version=c2ac667358708d7cce64c78f58af6adf4c1e848b <8c9fcc6c33950d3db551af664d1fd3d998bfee56; version=c2ac667358708d7cce64c78f58af6adf4c1e848b <d16f089bd700f45d720ce989d5495e1dc3be0cf8

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

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

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No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

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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