VulnerabilityPublished 18 Oct 2026

CVE-2026-98557: Linux kernel · gve: DQO: fix header length used by gve_can_send_tso() for UDP GSO

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in feab3880a72b43913d332c06b75bb80526fa47ba : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:47 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in feab3880a72b43913d332c06b75bb80526fa47ba, dc9e8964a21f20620dbfca4ef3e11eefa7be6451, 83769c23fb1879edc916a526ba424285033baf2d

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Linux kernel to feab3880a72b43913d332c06b75bb80526fa47ba, dc9e8964a21f20620dbfca4ef3e11eefa7be6451 or 83769c23fb1879edc916a526ba424285033baf2d.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 2f855c52a2e1d3c40d186549ac46cbd88b38eb49, < feab3880a72b43913d332c06b75bb80526fa47ba	Fixed in feab3880a72b43913d332c06b75bb80526fa47ba
LinuxLinux	Affected ≥ 014c607f86abc903d7bf46e13373d89392e371fe, < dc9e8964a21f20620dbfca4ef3e11eefa7be6451	Fixed in dc9e8964a21f20620dbfca4ef3e11eefa7be6451
LinuxLinux	Affected ≥ 014c607f86abc903d7bf46e13373d89392e371fe, < 83769c23fb1879edc916a526ba424285033baf2d	Fixed in 83769c23fb1879edc916a526ba424285033baf2d
LinuxLinux	Affected =7.1	Fixed in–

AI-suggested

The vulnerability is fixed in the Linux kernel by commits feab3880a72b43913d332c06b75bb80526fa47ba, dc9e8964a21f20620dbfca4ef3e11eefa7be6451, and 83769c23fb1879edc916a526ba424285033baf2d. Users and administrators should update to a kernel version that includes these fixes. No other mitigation or workaround is indicated.

Description

A vulnerability in the Linux kernel's gve driver related to UDP Generic Segmentation Offload (GSO) was fixed. The function gve_can_send_tso() incorrectly calculates the header length for UDP GSO packets by using a TCP header length function, leading to miscalculated segment boundaries. This can cause the driver to either unnecessarily disable GSO or to hand the device packets with segments spanning too many buffers, potentially causing malfunction. The issue is fixed by correctly using the UDP header length for these packets.

Impact

Incorrect header length calculation can lead to two main issues: (1) unnecessary disabling of UDP GSO, causing performance degradation due to additional segmentation by the network stack, and (2) the device receiving packets with segments spanning more buffers than supported, which could cause transmission errors or driver malfunction. There is no indication of remote code execution or privilege escalation. No known exploits in the wild have been reported.

Summary

The Linux kernel gve driver had a flaw in gve_can_send_tso() where it used skb_tcp_all_headers() to determine header length for UDP GSO packets, which lack a TCP header. This caused tcp_hdrlen() to read incorrect data, resulting in header lengths ranging from 0 to 60 bytes instead of the correct transport offset plus UDP header length. Consequently, segment boundaries were miscalculated, causing either unnecessary disabling of GSO or segments exceeding the maximum buffer descriptors (GVE_TX_MAX_DATA_DESCS). The fix involves using the UDP header length for SKB_GSO_UDP_L4 packets, aligning with gve_prep_tso()'s behavior. The vulnerability affects Linux kernel version 7.1 and was resolved in specific commits identified by their hashes.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 10:38 UTC

Technical details

References

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