VulnerabilityPublished 18 Oct 2026

CVE-2026-98556: Linux kernel · gve: DQO: reject TSO packets with an out of range MSS

Source GCVE Database

Authoritative record:CVE-2026-98556· Medium

Not known to be exploited · fixed in c517e8755960c8c6335ebf7dae6c95c43e5fb085 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 17:16 UTC

Severity

Medium

Rated by Threat Radar · 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 c517e8755960c8c6335ebf7dae6c95c43e5fb085, 296c83b5ccc808c080865eb20fd7a477b0355bb7, 2dc3ae3942e151fef254b7bbb65c832192ad2069

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.

ghsa-jwgx-gfj4-hvfm

What to do

Upgrade Linux kernel to c517e8755960c8c6335ebf7dae6c95c43e5fb085, 296c83b5ccc808c080865eb20fd7a477b0355bb7 or 2dc3ae3942e151fef254b7bbb65c832192ad2069.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ a57e5de476be0b4b7f42beb6a21c19ad9c577aa3, < c517e8755960c8c6335ebf7dae6c95c43e5fb085	Fixed in c517e8755960c8c6335ebf7dae6c95c43e5fb085
LinuxLinux	Affected ≥ a57e5de476be0b4b7f42beb6a21c19ad9c577aa3, < 296c83b5ccc808c080865eb20fd7a477b0355bb7	Fixed in 296c83b5ccc808c080865eb20fd7a477b0355bb7
LinuxLinux	Affected ≥ a57e5de476be0b4b7f42beb6a21c19ad9c577aa3, < 2dc3ae3942e151fef254b7bbb65c832192ad2069	Fixed in 2dc3ae3942e151fef254b7bbb65c832192ad2069
LinuxLinux	Affected =5.14	Fixed in–

AI-suggested

A fix is available that drops TSO packets with out-of-range MSS values in the gve_prep_tso() function and adjusts feature checks to avoid improper segmentation. Users should apply the official Linux kernel updates that include this fix. Since this is a kernel-level vulnerability, updating to the patched kernel version is the recommended remediation. No additional action is required beyond applying the official fix.

Description

A vulnerability in the Linux kernel's gve driver related to TSO packet handling has been resolved. The gve_prep_tso() function did not enforce the maximum segment size (MSS) limit of 9728 bytes, assuming the hypervisor-enforced 9K MTU and 64KB TSO size limit were sufficient. However, packets not generated locally, such as those from guests behind a tap or packet socket users, could specify an arbitrary gso_size, potentially causing MSS to be set incorrectly. This could lead to MSS being zero due to a 14-bit field overflow. The fix drops such packets and adjusts feature checks to prevent improper segmentation. The issue is specific to GSO packets and MTU checks in the forwarding path and is addressed separately for non-TSO packets.

Impact

This vulnerability could allow malformed or oversized TSO packets with out-of-range MSS values to be processed incorrectly by the gve driver, potentially causing unexpected behavior or packet handling errors. The issue arises from the lack of MSS enforcement and improper handling of GSO packet sizes, which could affect packet segmentation and transmission. However, the vulnerability is mitigated by dropping such packets, preventing malformed packets from being processed by the device.

References

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