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VulnerabilityPublished Updated

CVE-2026-99078: Linux kernel · net/mlx5e: Prevent stale XSK buffer release on MPWQE refill retry

Source GCVE Database

0
Authoritative record:CVE-2026-99078· Critical 9.8

Not known to be exploited · CVSS 9.8 Critical · fixed in f3a52e2ec2788a7f6b64137985c087188a54ad4f : patch Linux kernel as a priority.

Data as of 26 Oct 2026, 14:05 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 f3a52e2ec2788a7f6b64137985c087188a54ad4f, d215d09606b0fcd18ad1eb532995782a21cea49d, 867119b4b588037724b85839d534465f0334d9bd +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
  • ≥ 4c2a1323680709078736a2886c754004e9fe42e6, < f3a52e2ec2788a7f6b64137985c087188a54ad4f
Fixed in
  • f3a52e2ec2788a7f6b64137985c087188a54ad4f
LinuxLinuxAffected
  • ≥ 4c2a1323680709078736a2886c754004e9fe42e6, < d215d09606b0fcd18ad1eb532995782a21cea49d
Fixed in
  • d215d09606b0fcd18ad1eb532995782a21cea49d
LinuxLinuxAffected
  • ≥ 4c2a1323680709078736a2886c754004e9fe42e6, < 867119b4b588037724b85839d534465f0334d9bd
Fixed in
  • 867119b4b588037724b85839d534465f0334d9bd
LinuxLinuxAffected
  • ≥ 4c2a1323680709078736a2886c754004e9fe42e6, < 63811edf512584c946e5e96b100e9e280703bbb5
Fixed in
  • 63811edf512584c946e5e96b100e9e280703bbb5
LinuxLinuxAffected
  • ≥ 4c2a1323680709078736a2886c754004e9fe42e6, < 3d73a1164a8c6b4461907a65cb6c022ea4fd39af
Fixed in
  • 3d73a1164a8c6b4461907a65cb6c022ea4fd39af
LinuxLinuxAffected
  • =6.4
Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Prevent stale XSK buffer release on MPWQE refill retry With AF_XDP on a striding RQ, mlx5e defers releasing XSK buffers until an MPWQE is refilled. If XSK allocation then returns -ENOMEM, actual_wq_head is not advanced and a later NAPI poll retries the same WQE. mlx5e_free_rx_mpwqe() leaves each released slot marked as releasable. On retry it can therefore call xsk_buff_free() again through stale pointers after the frames have returned to the XSK pool and been reallocated. Set all skip_release_bitmap bits in the common error path of mlx5e_xsk_alloc_rx_mpwqe(). This matches mlx5e_alloc_rx_mpwqe(). A successful allocation already clears the bitmap after replacing every buffer, so retries become idempotent without changing the success path. Fault injection forced three consecutive failures for one selected MPWQE. Both an early allocation failure and a partial 8-of-16-buffer unwind released the original 16 XSK buffers only once. Each error left a full bitmap, the following NAPI retry skipped the release, and a later successful allocation cleared it. A 20-second AF_XDP zero-copy pressure run exercised 1,575,262 buffer allocation failures without invalid descriptors, WQE errors, or kernel warnings.

References

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