CVE-2026-98288

Malformed TCP transmission via truncated TSO header length

Published Oct 6, 2026 · Updated Oct 6, 2026

Incorrect packet transmission in the Linux stmmac driver allows local users to generate malformed TCP/IPv6 output through TSO. stmmac_tso_xmit() narrows a protocol-header length to eight bits even though stmmac_tso_valid_packet() accepts up to 1023 bytes, causing TSO descriptors to treat part of an oversized header as payload. Triggering requires stmmac hardware TSO and a locally created TCP/IPv6 socket with sufficiently long destination or hop-by-hop options; the documented consequence is incorrect packet segmentation, not a demonstrated host crash.

CVSS severityUnavailable
Unscored
EPSS probability0.16%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect packet transmission in the Linux stmmac driver allows local users to generate malformed TCP/IPv6 output through TSO. stmmac_tso_xmit() narrows a protocol-header length to eight bits even though stmmac_tso_valid_packet() accepts up to 1023 bytes, causing TSO descriptors to treat part of an oversized header as payload. Triggering requires stmmac hardware TSO and a locally created TCP/IPv6 socket with sufficiently long destination or hop-by-hop options; the documented consequence is incorrect packet segmentation, not a demonstrated host crash.

The record

CVE
CVE-2026-98288
Published
Oct 6, 2026
Updated
Oct 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
Unavailable

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=4.13
  2. Affected versionversion=9edfa7dab8112a012b349b7937f5444fdc21e8f9 <15989abd74f16f44bf953d056b95f1d2fda9b0cd
  3. Affected versionversion=9edfa7dab8112a012b349b7937f5444fdc21e8f9 <bcf6013c2b4d732c6e4bf4d0f6ae4a18d63d414b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=4.13; version=9edfa7dab8112a012b349b7937f5444fdc21e8f9 <15989abd74f16f44bf953d056b95f1d2fda9b0cd; version=9edfa7dab8112a012b349b7937f5444fdc21e8f9 <bcf6013c2b4d732c6e4bf4d0f6ae4a18d63d414b

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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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