CVE-2026-98236: Linux kernel · net: wwan: mhi_wwan_mbim: check skb_copy_bits() return value
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 28 Oct 2026, 01:27 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Exploitation 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.
Description
In the Linux kernel, the following vulnerability has been resolved: net: wwan: mhi_wwan_mbim: check skb_copy_bits() return value mhi_mbim_rx() ignores the return value of skb_copy_bits() when it copies each datagram out of the NTB. The datagram offset and length come from the DPE, which is only checked to lie within the NTB itself, so a modem can point a datagram outside the received skb. The copy then fails and the freshly allocated skbn is passed to netif_rx() with its uninitialized contents still in place, leaking kernel heap memory into the network stack. Free the skb and account an error when the copy fails. Verified in a QEMU guest with a fault injector pointing a DPE outside the received NTB: the copy fails, and the unpatched driver hands the uninitialized skbn to the network stack (observed as "unknown protocol" on bytes that were never written). With this check the failed datagram is dropped and counted as an rx error. Changes in v2: factor the free-and-count sequence out into mhi_mbim_rx_drop(), shared with the unknown-protocol path, as suggested by Loic Poulain.
References
- ubuntu.com/security/CVE-2026-98236 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98236 (opens in a new tab)
- git.kernel.org/linus/31550d585589fde1ae95bf7f7a8188b2d2fdf1c7 (opens in a new tab)
- git.kernel.org/stable/c/02eba5f36d20283f144f75d47f0354a85e4f78f0 (opens in a new tab)
- git.kernel.org/stable/c/298659c3677bf622afa9d77549cb4a967f9541e9 (opens in a new tab)
- git.kernel.org/stable/c/31550d585589fde1ae95bf7f7a8188b2d2fdf1c7 (opens in a new tab)
- git.kernel.org/stable/c/350fd3125ee26b5243935fd9e2b4d162ffba430a (opens in a new tab)
- git.kernel.org/stable/c/650af68435eaee783824457d2ef78cc5c03c1e88 (opens in a new tab)
- git.kernel.org/stable/c/7e98216e9da08b79e07a514d2a4f7646f8c9ccb9 (opens in a new tab)
- git.kernel.org/stable/c/dd136f1fdd1059f3bc25ede3a8def8f0ee151ce7 (opens in a new tab)