CVE-2026-98239: Linux kernel · net: lan743x: fix RX checksum use-after-free
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.1 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 37% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 6 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 is available and has been applied to the affected linux-hwe-edge kernel versions listed. Users should update to the fixed kernel versions to remediate this vulnerability. No additional mitigation steps are indicated.
Description
A use-after-free vulnerability in the Linux kernel's lan743x network driver was fixed. The flaw occurs in lan743x_rx_process_buffer() when handling multi-buffer receive packets, leading to a write after free of skb fragment metadata. This can happen after a live MTU increase when old buffer sizes persist. The issue was confirmed by a KUnit test and resolved by setting ip_summed on the surviving head skb instead of the freed fragment. The fix was applied to specific linux-hwe-edge kernel versions.
References
- ubuntu.com/security/CVE-2026-98239 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98239 (opens in a new tab)
- git.kernel.org/linus/a9ce4053dc945c5372dedba5017ee675b30dc0c5 (opens in a new tab)
- git.kernel.org/stable/c/0e52886c4324c9897c2c62f92be3dc8316cee67e (opens in a new tab)
- git.kernel.org/stable/c/161a403c8625e152de03d1da22bbf9cda6dc9f9f (opens in a new tab)
- git.kernel.org/stable/c/5c216bfa9fb7b36804485e67975e9c98055b31ef (opens in a new tab)
- git.kernel.org/stable/c/6fe5c3a2503983abb431d93faeadfc7f5e6a7e33 (opens in a new tab)
- git.kernel.org/stable/c/a58024835c704419bb46d2a34e5223f65605f958 (opens in a new tab)
- git.kernel.org/stable/c/a9ce4053dc945c5372dedba5017ee675b30dc0c5 (opens in a new tab)