CVE-2026-99079: Linux kernel · net/mlx5e: Prevent stale XSK buffer release on refill retry
Source GCVE Database
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
- 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:HExploitation evidence
Disclosed: evidence found.
CVE published 23 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| 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
- nvd.nist.gov/vuln/detail/CVE-2026-99079 (opens in a new tab)
- git.kernel.org/stable/c/32bbb870078d467479965c21bbc4960c57eea208 (opens in a new tab)
- git.kernel.org/stable/c/34d1db2b18e1c1d189e34dd51923e031815f88e3 (opens in a new tab)
- git.kernel.org/stable/c/639522e5056cade578a324acfa993ec6c9f7f5dc (opens in a new tab)
- git.kernel.org/stable/c/655f47477054d19de3b138840be229a1a4490d0c (opens in a new tab)
- git.kernel.org/stable/c/e01620844c5c88b6fcf819d171df8e3976a0e76f (opens in a new tab)