CVE-2026-98278

Kernel warning via self-routing tunnel offload

Published Oct 6, 2026 · Updated Oct 6, 2026

A kernel warning in Linux 6.19 through 7.2.7 allows local users with CAP_NET_ADMIN to trigger WARN_ON_ONCE through IP tunnel flowtable offload. The dev_fill_forward_path() loop check warns when tunnel endpoint routing returns the tunnel itself, leaving the forward-path walk unable to advance. The warning requires a self-routing tunnel and an offload attempt; it causes a kernel panic only where panic_on_warn is enabled.

CVSS severityUnavailable
Unscored
EPSS probability0.18%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A kernel warning in Linux 6.19 through 7.2.7 allows local users with CAP_NET_ADMIN to trigger WARN_ON_ONCE through IP tunnel flowtable offload. The dev_fill_forward_path() loop check warns when tunnel endpoint routing returns the tunnel itself, leaving the forward-path walk unable to advance. The warning requires a self-routing tunnel and an offload attempt; it causes a kernel panic only where panic_on_warn is enabled.

The record

CVE
CVE-2026-98278
Published
Oct 6, 2026
Updated
Oct 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
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

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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=6.19
  2. Affected versionversion=ab427db17885814069bae891834f20842f0ac3a4 <150dba2c69e93302af24a0c868eebe4871e2e107
  3. Affected versionversion=ab427db17885814069bae891834f20842f0ac3a4 <d8eb177632dacda28bc6130c2105afbf5b791eb0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=6.19; version=ab427db17885814069bae891834f20842f0ac3a4 <150dba2c69e93302af24a0c868eebe4871e2e107; version=ab427db17885814069bae891834f20842f0ac3a4 <d8eb177632dacda28bc6130c2105afbf5b791eb0

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 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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