Status: UPDATED | Advisory ID: CVE-2026-98239
| CVE | CVE-2026-98239 |
| CVSS Score / Version | 8.1 (High) / CVSS v3.1 |
| Updated | 2026-10-07 |
| CVSS Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| CVSS Prose | attack vector is network; attack complexity is high; privileges required is none; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high. |
| Affected products | Linux Kernel |
| Vendor | Product | Affected Versions | Patch Status |
|---|---|---|---|
| Linux | Linux Kernel |
| Subsystems | OT Supporting Infrastructure |
| Sectors | All Sectors |
In the Linux kernel, the following vulnerability has been resolved:
net: lan743x: fix RX checksum use-after-free
lan743x_rx_process_buffer() adds each non-first receive buffer to the
head skb's frag_list. On the last descriptor, lan743x_rx_trim_skb()
linearizes the head and frees the fragment skb metadata.
The checksum-success path then writes ip_summed through the local skb
pointer, which still points to the final fragment. This causes a
use-after-free write when a packet spans more than one receive buffer.
Set ip_summed on the surviving head skb instead. Multi-buffer receive
can occur after a live MTU increase because existing ring entries keep
their old buffer size until they are replenished.
A KUnit test invoking lan743x_rx_process_buffer() with a two-buffer
packet produced a one-byte KASAN use-after-free write before this change.
The same test passed after the change. The driver object also builds
with W=1. This was not tested on physical LAN743x hardware. (NVD)
Monitor Linux's web page for any future patch releases.
| Source | Reference |
|---|---|
| NVD | https://nvd.nist.gov/vuln/detail/CVE-2026-98239 |
| CVE | https://www.cve.org/CVERecord?id=CVE-2026-98239 |