CVE-2026-46273 - Vulnerability Details

- ibmveth: Disable GSO for packets with small MSS

Description

In the Linux kernel, the following vulnerability has been resolved:

ibmveth: Disable GSO for packets with small MSS

Some physical adapters on Power systems do not support segmentation
offload when the MSS is less than 224 bytes. Attempting to send such
packets causes the adapter to freeze, stopping all traffic until
manually reset.

Implement ndo_features_check to disable GSO for packets with small MSS
values. The network stack will perform software segmentation instead.

The 224-byte minimum matches ibmvnic
commit <f10b09ef687f> ("ibmvnic: Enforce stronger sanity checks
on GSO packets")
which uses the same physical adapters in SEA configurations.

The issue occurs specifically when the hardware attempts to perform
segmentation (gso_segs > 1) with a small MSS. Single-segment GSO packets
(gso_segs == 1) do not trigger the problematic LSO code path and are
transmitted normally without segmentation.

Add an ndo_features_check callback to disable GSO when MSS < 224 bytes.
Also call vlan_features_check() to ensure proper handling of VLAN packets,
particularly QinQ (802.1ad) configurations where the hardware parser may
not support certain offload features.

Validated using iptables to force small MSS values. Without the fix,
the adapter freezes. With the fix, packets are segmented in software
and transmission succeeds. Comprehensive regression testing completedd
(MSS tests, performance, stability).

Published: 2026-06-03

Score: 8.6 High

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Impact

In the Linux kernel, physical adapters on IBM Power systems that lack support for segmentation offloading when the maximum segment size is less than 224 bytes can become locked when such packets are transmitted. The issue allows the network stack to request hardware general segmentation offload (GSO) for these packets, causing the adapter to freeze and halt all traffic until a manual reset. Adding an ndo_features_check routine disables GSO for MSS values below 224, causing the stack to perform software segmentation instead and eliminating the freeze. This flaw is identified as CWE‑1284, highlighting improper handling of segmentation offloading parameters.

Affected Systems

Affected systems include Linux kernels running on IBM Power Architecture platforms that use the ibmveth or ibmvnic drivers. Any kernel version preceding the commit that introduced the ndo_features_check and VLAN handling patch is vulnerable. Updating to a kernel that incorporates those changes removes the risk.

Risk and Exploitability

The CVSS score of 8.6 indicates a high severity. The EPSS score of <1% indicates a very low likelihood of exploitation currently, and the vulnerability is not listed in the CISA KEV catalog. An attacker with network access could trigger the denial of service by sending a packet with an MSS lower than 224 bytes, which would cause the physical adapter to freeze. Until the patch is applied, the risk remains significant.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Linux

unaffected

Version	Status	Constraints
`8641dd85799f85bef5f0d1f87356aaa12cb2195e`	affected	< 86fc64584811d43c9ccd74447de58620189d8b77
`8641dd85799f85bef5f0d1f87356aaa12cb2195e`	affected	< 9a5e984d7af910e46dcbed3ce77873e000a4f77d
`8641dd85799f85bef5f0d1f87356aaa12cb2195e`	affected	< 1cdf5dbcec988d06f5f720bdf89e91073f77fa10
`8641dd85799f85bef5f0d1f87356aaa12cb2195e`	affected	< 82bc89fbb82d9396fb4eaee8720ea85e2e787957
`8641dd85799f85bef5f0d1f87356aaa12cb2195e`	affected	< db8012c631cb845e9ae2b4b531e17d86c9519755
`8641dd85799f85bef5f0d1f87356aaa12cb2195e`	affected	< c1f261863e65b508f37416dfbc5c5d911c9b9233
`8641dd85799f85bef5f0d1f87356aaa12cb2195e`	affected	< 3af24f0c4c31f18a4a2d927990759194832bb6e9
`8641dd85799f85bef5f0d1f87356aaa12cb2195e`	affected	< cc427d24ac6442ffdeafd157a63c7c5b73ed4de4

Linux

affected

Version	Status	Constraints
`4.2`	affected	—
`0`	unaffected	< 4.2
`5.10.258`	unaffected	≤ 5.10.*
`5.15.209`	unaffected	≤ 5.15.*
`6.1.175`	unaffected	≤ 6.1.*
`6.6.140`	unaffected	≤ 6.6.*
`6.12.88`	unaffected	≤ 6.12.*
`6.18.30`	unaffected	≤ 6.18.*
`7.0.7`	unaffected	≤ 7.0.*
`7.1`	unaffected	≤ *

Configuration 1 [-]

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel:7.1:rc1::::::

No data.

Vendor Product Confidence Versions

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`[8641dd85799f85bef5f0d1f87356aaa12cb2195e,86fc64584811d43c9ccd74447de58620189d8b77)`	affected	code_commit	—
`[8641dd85799f85bef5f0d1f87356aaa12cb2195e,9a5e984d7af910e46dcbed3ce77873e000a4f77d)`	affected	code_commit	—
`[8641dd85799f85bef5f0d1f87356aaa12cb2195e,1cdf5dbcec988d06f5f720bdf89e91073f77fa10)`	affected	code_commit	—
`[8641dd85799f85bef5f0d1f87356aaa12cb2195e,82bc89fbb82d9396fb4eaee8720ea85e2e787957)`	affected	code_commit	—
`[8641dd85799f85bef5f0d1f87356aaa12cb2195e,db8012c631cb845e9ae2b4b531e17d86c9519755)`	affected	code_commit	—
`[8641dd85799f85bef5f0d1f87356aaa12cb2195e,c1f261863e65b508f37416dfbc5c5d911c9b9233)`	affected	code_commit	—
`[8641dd85799f85bef5f0d1f87356aaa12cb2195e,3af24f0c4c31f18a4a2d927990759194832bb6e9)`	affected	code_commit	—
`[8641dd85799f85bef5f0d1f87356aaa12cb2195e,cc427d24ac6442ffdeafd157a63c7c5b73ed4de4)`	affected	code_commit	—

Linux

Linux Kernel

99%

Version	Status	Scheme	Platform
`4.2`	affected	generic	—
`[0,4.2)`	unaffected	semver	—
`[5.10.258,5.11.0)`	unaffected	semver	—
`[5.15.209,5.16.0)`	unaffected	semver	—
`[6.1.175,6.2.0)`	unaffected	semver	—
`[6.6.140,6.7.0)`	unaffected	semver	—
`[6.12.88,6.13.0)`	unaffected	semver	—
`[6.18.30,6.19.0)`	unaffected	semver	—
`[7.0.7,7.1.0)`	unaffected	semver	—
`[7.1-rc2,*]`	unaffected	generic	—

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Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

Apply a kernel update that includes the ibmveth and ibmvnic commit disabling GSO for MSS values below 224 bytes (c1f261863e65b508f37416dfbc5c5d911c9b9233), directly resolving the flaw identified as CWE‑1284.
Because the flaw is an improper handling of GSO parameters (CWE‑1284), disable GSO and related offloading features on affected interfaces using ethtool, e.g., `ethtool -K <iface> gso off tso off gro off tx off`.
Ensure that outbound packets have an MSS of at least 224 bytes, which mitigates the potential hardware freeze associated with CWE‑1284; adjust system or firewall rules, such as setting `net.ipv4.tcp_mtu_prot_min`, or using iptables to enforce an MSS of 224 bytes.

Generated by OpenCVE AI on June 9, 2026 at 18:33 UTC.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00389.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/stable/c/1cdf5dbcec988d06f5f720bdf89e91073f77fa10
https://git.kernel.org/stable/c/3af24f0c4c31f18a4a2d927990759194832bb6e9
https://git.kernel.org/stable/c/82bc89fbb82d9396fb4eaee8720ea85e2e787957
https://git.kernel.org/stable/c/86fc64584811d43c9ccd74447de58620189d8b77
https://git.kernel.org/stable/c/9a5e984d7af910e46dcbed3ce77873e000a4f77d
https://git.kernel.org/stable/c/c1f261863e65b508f37416dfbc5c5d911c9b9233
https://git.kernel.org/stable/c/cc427d24ac6442ffdeafd157a63c7c5b73ed4de4
https://git.kernel.org/stable/c/db8012c631cb845e9ae2b4b531e17d86c9519755
https://lore.kernel.org/linux-cve-announce/2026060327-CVE-2026-46273-e8d0@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2026-46273
https://www.cve.org/CVERecord?id=CVE-2026-46273

History

Tue, 09 Jun 2026 17:45:00 +0000

Type	Values Removed	Values Added
Weaknesses		NVD-CWE-noinfo
CPEs		cpe:2.3:o:linux:linux_kernel:7.1:rc1::::::

Fri, 05 Jun 2026 06:45:00 +0000

Type	Values Removed	Values Added
Metrics	cvssV3_1 `{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}`	cvssV3_1 `{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H'}`

Thu, 04 Jun 2026 02:15:00 +0000

Type	Values Removed	Values Added
Weaknesses	CWE-400

Thu, 04 Jun 2026 00:15:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-1284
References		https://lore.kernel.org/linux-cve-announce/2026060327-CVE-2026-46273-e8d0@gregkh/T https://nvd.nist.gov/vuln/detail/CVE-2026-46273 https://www.cve.org/CVERecord?id=CVE-2026-46273
Metrics	threat_severity `None`	cvssV3_1 `{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}` threat_severity `Moderate`

Wed, 03 Jun 2026 19:00:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-400

Wed, 03 Jun 2026 17:45:00 +0000

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: ibmveth: Disable GSO for packets with small MSS Some physical adapters on Power systems do not support segmentation offload when the MSS is less than 224 bytes. Attempting to send such packets causes the adapter to freeze, stopping all traffic until manually reset. Implement ndo_features_check to disable GSO for packets with small MSS values. The network stack will perform software segmentation instead. The 224-byte minimum matches ibmvnic commit <f10b09ef687f> ("ibmvnic: Enforce stronger sanity checks on GSO packets") which uses the same physical adapters in SEA configurations. The issue occurs specifically when the hardware attempts to perform segmentation (gso_segs > 1) with a small MSS. Single-segment GSO packets (gso_segs == 1) do not trigger the problematic LSO code path and are transmitted normally without segmentation. Add an ndo_features_check callback to disable GSO when MSS < 224 bytes. Also call vlan_features_check() to ensure proper handling of VLAN packets, particularly QinQ (802.1ad) configurations where the hardware parser may not support certain offload features. Validated using iptables to force small MSS values. Without the fix, the adapter freezes. With the fix, packets are segmented in software and transmission succeeds. Comprehensive regression testing completedd (MSS tests, performance, stability).
Title		ibmveth: Disable GSO for packets with small MSS
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/1cdf5dbcec988d06f5f720bdf89e91073f77fa10 https://git.kernel.org/stable/c/3af24f0c4c31f18a4a2d927990759194832bb6e9 https://git.kernel.org/stable/c/82bc89fbb82d9396fb4eaee8720ea85e2e787957 https://git.kernel.org/stable/c/86fc64584811d43c9ccd74447de58620189d8b77 https://git.kernel.org/stable/c/9a5e984d7af910e46dcbed3ce77873e000a4f77d https://git.kernel.org/stable/c/c1f261863e65b508f37416dfbc5c5d911c9b9233 https://git.kernel.org/stable/c/cc427d24ac6442ffdeafd157a63c7c5b73ed4de4 https://git.kernel.org/stable/c/db8012c631cb845e9ae2b4b531e17d86c9519755

Subscriptions

Linux Linux Kernel

MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2026-06-03T16:19:18.056Z

Updated: 2026-06-14T18:05:30.074Z

Reserved: 2026-05-13T15:03:33.109Z

Link: CVE-2026-46273

Vulnrichment

No data.

NVD

Status : Analyzed

Published: 2026-06-03T18:16:29.160

Modified: 2026-06-09T17:31:31.780

Link: CVE-2026-46273

Redhat

Severity : Moderate

Publid Date: 2026-06-03T00:00:00Z

Links: CVE-2026-46273 - Bugzilla

OpenCVE Enrichment

Updated: 2026-06-09T18:45:06Z

Weaknesses

CWE-1284
Improper Validation of Specified Quantity in Input
NVD-CWE-noinfo

Impact

Affected Systems

Risk and Exploitability

Tracking

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

Subscriptions

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