CVE-2026-99079: Linux Vulnerability (CVSS 9.8)

Description

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Prevent stale XSK buffer release on refill retry When an XDP redirect to an AF_XDP socket fails because its RX ring is full, the XSK core frees the buffer. During the subsequent batched refill of a legacy cyclic RQ, mlx5e also releases the WQE's XSK buffer before allocating a replacement. If that refill succeeds only partially, a WQE left without a replacement retains its old buffer pointer. The buffer can meanwhile be allocated to another WQE. A later refill retry can then free the live buffer through the stale pointer and publish the same UMEM frame twice. Mark the WQE as released immediately after the driver-side free. The flag is already cleared when a replacement buffer is assigned, so refill retries no longer release stale pointers. The failure is silent and produces no kernel warning or splat. A standalone legacy cyclic-RQ zero-copy libxsk reproducer, using 64-byte UDP traffic offered at 12 Mpps, detected it: stock stopped after 2,854,914 packets in 4.094 seconds, with 4,542 xdp_rx_ring_full events and 64 ownership/double-publication errors. With this change it processed 356,904,225 packets in 30 seconds despite 571,405 xdp_rx_ring_full events, with no ownership or data errors.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= 3f93f82988bc6b4104314bf9aa485d47fbb7e241, < 32bbb870078d467479965c21bbc4960c57eea208; >= 3f93f82988bc6b4104314bf9aa485d47fbb7e241, < 34d1db2b18e1c1d189e34dd51923e031815f88e3; >= 3f93f82988bc6b4104314bf9aa485d47fbb7e241, < 639522e5056cade578a324acfa993ec6c9f7f5dc; >= 3f93f82988bc6b4104314bf9aa485d47fbb7e241, < 655f47477054d19de3b138840be229a1a4490d0c; >= 3f93f82988bc6b4104314bf9aa485d47fbb7e241, < e01620844c5c88b6fcf819d171df8e3976a0e76f
Linux	Linux	6.4

References

Timeline

Published: Oct 23, 2026
Last Modified: Oct 24, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-99079?

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Prevent stale XSK buffer release on refill retry When an XDP redirect to an AF_XDP socket fails because its RX ring is full, the XSK core frees the buffer. During the subsequent batched refill of a legacy cyclic RQ, mlx5e also releases the WQE's XSK buffer before allocating a replacement. If that refill succeeds only partially, a WQE left without a replacement retains its old buffer pointer. The buffer can meanwhile be allocated to another WQE. A later refill retry can then free the live buffer through the stale pointer and publish the same UMEM frame twice. Mark the WQE as released immediately after the driver-side free. The flag is already cleared when a replacement buffer is assigned, so refill retries no longer release stale pointers. The failure is silent and produces no kernel warning or splat. A standalone legacy cyclic-RQ zero-copy libxsk reproducer, using 64-byte UDP traffic offered at 12 Mpps, detected it: stock stopped after 2,854,914 packets in 4.094 seconds, with 4,542 xdp_rx_ring_full events and 64 ownership/double-publication errors. With this change it processed 356,904,225 packets in 30 seconds despite 571,405 xdp_rx_ring_full events, with no ownership or data errors.

How severe is CVE-2026-99079?

CVE-2026-99079 has a CVSS score of 9.8/10 (CRITICAL severity).

How do I fix CVE-2026-99079?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2026

View all 2026CVEs →