SB20261023218 - Out-of-bounds read in Linux kernel __virtio_net_hdr_to_skb() and skb_gso_transport_seglen()

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds read (CVE-ID: CVE-2026-98954)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to trigger out-of-bounds reads in kernel memory, potentially causing a denial of service.

The vulnerability exists due to an out-of-bounds read in the Linux kernel's GSO packet processing when handling specially crafted packets without VIRTIO_NET_HDR_F_NEEDS_CSUM. A local user can supply malformed packets through an affected virtio network header processing path to bypass flow dissection in __virtio_net_hdr_to_skb(), leaving the transport header unset or outside linear packet data and triggering an out-of-bounds read in skb_gso_transport_seglen().

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/44378d02c5aaae24b60a75fbbb539b4aa4db503d
• https://git.kernel.org/stable/c/5f4dfdf0077730e9d3ef5b37ceb17a5a56d6f34c