Linux Kernel up to 7.1-rc1 ibmveth vlan_features_check stack-based overflow

CVSS Meta Temp Score
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8.1$0-$5k0.00

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 7.1-rc1. The impacted element is the function vlan_features_check of the component ibmveth. Such manipulation leads to stack-based overflow. This vulnerability is referenced as CVE-2026-46273. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 7.1-rc1. Affected by this issue is the function vlan_features_check of the component ibmveth. The manipulation with an unknown input leads to a stack-based overflow vulnerability. Using CWE to declare the problem leads to CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). Impacted is confidentiality, integrity, and availability. CVE summarizes:

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).

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-46273 since 05/13/2026. The exploitation is known to be easy. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 06/22/2026).

The vulnerability scanner Nessus provides a plugin with the ID 321690 (SUSE SLES12 Security Update : kernel (SUSE-SU-2026:2450-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.88, 6.18.30, 7.0.7 or 7.1-rc2 eliminates this vulnerability. Applying the patch 86fc64584811d43c9ccd74447de58620189d8b77/9a5e984d7af910e46dcbed3ce77873e000a4f77d/1cdf5dbcec988d06f5f720bdf89e91073f77fa10/82bc89fbb82d9396fb4eaee8720ea85e2e787957/db8012c631cb845e9ae2b4b531e17d86c9519755/c1f261863e65b508f37416dfbc5c5d911c9b9233/3af24f0c4c31f18a4a2d927990759194832bb6e9/cc427d24ac6442ffdeafd157a63c7c5b73ed4de4 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (321690) and CERT Bund (WID-SEC-2026-1802). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

  • Open Source Linux Kernel

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.3
VulDB Meta Temp Score: 8.1

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.6
CNA Vector (Linux): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Stack-based overflow
CWE: CWE-121 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 321690
Nessus Name: SUSE SLES12 Security Update : kernel (SUSE-SU-2026:2450-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.258/5.15.209/6.1.175/6.6.140/6.12.88/6.18.30/7.0.7/7.1-rc2
Patch: 86fc64584811d43c9ccd74447de58620189d8b77/9a5e984d7af910e46dcbed3ce77873e000a4f77d/1cdf5dbcec988d06f5f720bdf89e91073f77fa10/82bc89fbb82d9396fb4eaee8720ea85e2e787957/db8012c631cb845e9ae2b4b531e17d86c9519755/c1f261863e65b508f37416dfbc5c5d911c9b9233/3af24f0c4c31f18a4a2d927990759194832bb6e9/cc427d24ac6442ffdeafd157a63c7c5b73ed4de4

Timelineinfo

05/13/2026 CVE reserved
06/03/2026 +21 days Advisory disclosed
06/03/2026 +0 days VulDB entry created
06/22/2026 +19 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-46273 (🔒)
GCVE (CVE): GCVE-0-2026-46273
GCVE (VulDB): GCVE-100-368210
CERT Bund: WID-SEC-2026-1802 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 06/03/2026 21:47
Updated: 06/22/2026 17:19
Changes: 06/03/2026 21:47 (59), 06/06/2026 02:55 (7), 06/08/2026 05:45 (12), 06/22/2026 17:19 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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