CVE-2026-46273
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).
INFO
Published Date :
June 3, 2026, 6:16 p.m.
Last Modified :
June 3, 2026, 6:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-46273
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Implement ndo_features_check to disable GSO for MSS < 224 bytes.
- Ensure proper handling of VLAN packets using vlan_features_check().
- Rely on software segmentation for smaller packets.
- Apply the kernel patch for ibmveth driver.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-46273.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-46273 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-46273
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-46273 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-46273 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 03, 2026
Action Type Old Value New Value 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). Added Reference https://git.kernel.org/stable/c/1cdf5dbcec988d06f5f720bdf89e91073f77fa10 Added Reference https://git.kernel.org/stable/c/3af24f0c4c31f18a4a2d927990759194832bb6e9 Added Reference https://git.kernel.org/stable/c/82bc89fbb82d9396fb4eaee8720ea85e2e787957 Added Reference https://git.kernel.org/stable/c/86fc64584811d43c9ccd74447de58620189d8b77 Added Reference https://git.kernel.org/stable/c/9a5e984d7af910e46dcbed3ce77873e000a4f77d Added Reference https://git.kernel.org/stable/c/c1f261863e65b508f37416dfbc5c5d911c9b9233 Added Reference https://git.kernel.org/stable/c/cc427d24ac6442ffdeafd157a63c7c5b73ed4de4 Added Reference https://git.kernel.org/stable/c/db8012c631cb845e9ae2b4b531e17d86c9519755