Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

Go to Calendar     Go to Press Room     Go to Newsletters subscription

CVE-2026-68123

Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
10/08/2026
Last modified:
19/08/2026

Description

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> openvswitch: fix GSO userspace truncation underflow<br /> <br /> OVS_ACTION_ATTR_TRUNC currently stores a delta from the original skb<br /> length in OVS_CB(skb)-&gt;cutlen. When a later userspace action segments a<br /> GSO skb, queue_gso_packets() reuses that delta for each smaller segment.<br /> A segment can then reach queue_userspace_packet() with cutlen greater<br /> than skb-&gt;len, underflowing the length passed to skb_zerocopy().<br /> <br /> Store the maximum preserved length instead and bound each consumer<br /> against the current skb length. Use U32_MAX as the no-truncation<br /> sentinel so the value remains valid if skb geometry changes before a<br /> consumer handles it.

Impact

Vector 3.x
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 9.80 CRITICAL
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x
9.80
Severity 3.x
CRITICAL

References to Advisories, Solutions, and Tools