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VulnerabilityPublished Updated

CVE-2026-99079: Linux kernel · net/mlx5e: Prevent stale XSK buffer release on refill retry

Source GCVE Database

0
Authoritative record:CVE-2026-99079· Critical 9.8

Not known to be exploited · CVSS 9.8 Critical · fixed in e01620844c5c88b6fcf819d171df8e3976a0e76f : patch Linux kernel as a priority.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in e01620844c5c88b6fcf819d171df8e3976a0e76f, 639522e5056cade578a324acfa993ec6c9f7f5dc, 655f47477054d19de3b138840be229a1a4490d0c +2
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 23 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 3f93f82988bc6b4104314bf9aa485d47fbb7e241, < e01620844c5c88b6fcf819d171df8e3976a0e76f
Fixed in
  • e01620844c5c88b6fcf819d171df8e3976a0e76f
LinuxLinuxAffected
  • ≥ 3f93f82988bc6b4104314bf9aa485d47fbb7e241, < 639522e5056cade578a324acfa993ec6c9f7f5dc
Fixed in
  • 639522e5056cade578a324acfa993ec6c9f7f5dc
LinuxLinuxAffected
  • ≥ 3f93f82988bc6b4104314bf9aa485d47fbb7e241, < 655f47477054d19de3b138840be229a1a4490d0c
Fixed in
  • 655f47477054d19de3b138840be229a1a4490d0c
LinuxLinuxAffected
  • ≥ 3f93f82988bc6b4104314bf9aa485d47fbb7e241, < 34d1db2b18e1c1d189e34dd51923e031815f88e3
Fixed in
  • 34d1db2b18e1c1d189e34dd51923e031815f88e3
LinuxLinuxAffected
  • ≥ 3f93f82988bc6b4104314bf9aa485d47fbb7e241, < 32bbb870078d467479965c21bbc4960c57eea208
Fixed in
  • 32bbb870078d467479965c21bbc4960c57eea208
LinuxLinuxAffected
  • =6.4
Fixed in–

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.

References

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