CVE-2026-99078: Linux kernel · net/mlx5e: Prevent stale XSK buffer release on MPWQE refill retry
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical.
Data as of 28 Oct 2026, 01:31 UTC
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
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix for this vulnerability is available and should be applied by updating to patched Linux kernel versions. The affected versions listed are specific kernel builds where the flaw existed. Users should upgrade to versions where this issue is resolved. No additional mitigation steps are indicated beyond applying the official fix.
Description
CVE-2026-99078 is a critical vulnerability in the Linux kernel's mlx5e network driver related to AF_XDP zero-copy buffer management. It involves a flaw where stale XSK buffers may be released multiple times during MPWQE refill retries, potentially causing memory corruption. The issue occurs when buffer allocation fails with -ENOMEM, leading to improper handling of buffer release bitmaps. This flaw has been resolved by ensuring idempotent retries through proper bitmap management.
References
- ubuntu.com/security/CVE-2026-99078 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-99078 (opens in a new tab)
- git.kernel.org/stable/c/3d73a1164a8c6b4461907a65cb6c022ea4fd39af (opens in a new tab)
- git.kernel.org/stable/c/63811edf512584c946e5e96b100e9e280703bbb5 (opens in a new tab)
- git.kernel.org/stable/c/867119b4b588037724b85839d534465f0334d9bd (opens in a new tab)
- git.kernel.org/stable/c/d215d09606b0fcd18ad1eb532995782a21cea49d (opens in a new tab)
- git.kernel.org/stable/c/f3a52e2ec2788a7f6b64137985c087188a54ad4f (opens in a new tab)