CVE-2026-99079net/mlx5e: Prevent stale XSK buffer release on refill retry
- 9.8CriticalCVSS base score
- 0.46%Exploitation in 30 daysEPSS · top 60% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By Linux
- 28 days later
· 28 days later
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Received | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.46% · top 60% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
- affected 3f93f82988bc6b4104314bf9aa485d47fbb7e241 – < 32bbb870078d467479965c21bbc4960c57eea208
- affected 3f93f82988bc6b4104314bf9aa485d47fbb7e241 – < 34d1db2b18e1c1d189e34dd51923e031815f88e3
- affected 3f93f82988bc6b4104314bf9aa485d47fbb7e241 – < 639522e5056cade578a324acfa993ec6c9f7f5dc
- affected 3f93f82988bc6b4104314bf9aa485d47fbb7e241 – < 655f47477054d19de3b138840be229a1a4490d0c
- affected 3f93f82988bc6b4104314bf9aa485d47fbb7e241 – < e01620844c5c88b6fcf819d171df8e3976a0e76f
- affected 6.4
- unaffected < 6.4
- unaffected 6.6.160 – ≤ 6.6.*
- unaffected 6.12.113 – ≤ 6.12.*
- unaffected 6.18.57 – ≤ 6.18.*
- unaffected 7.2.11 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References5
- https://git.kernel.org/stable/c/32bbb870078d467479965c21bbc4960c57eea208 (opens in a new tab)
- https://git.kernel.org/stable/c/34d1db2b18e1c1d189e34dd51923e031815f88e3 (opens in a new tab)
- https://git.kernel.org/stable/c/639522e5056cade578a324acfa993ec6c9f7f5dc (opens in a new tab)
- https://git.kernel.org/stable/c/655f47477054d19de3b138840be229a1a4490d0c (opens in a new tab)
- https://git.kernel.org/stable/c/e01620844c5c88b6fcf819d171df8e3976a0e76f (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-108745 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-99079)Record last updated .