CVE-2026-98008: Linux kernel · net: macb: fix NULL pointer dereference on unbind with fixed-link
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 12:55 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 25 Sep 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 that adds proper NULL pointer checks before calling mdiobus_unregister() and mdiobus_free() in the macb driver. Users should apply the updated Linux kernel versions that include this patch to prevent kernel crashes related to this issue.
Description
A NULL pointer dereference vulnerability was found and fixed in the Linux kernel's macb network driver. The issue occurs when the device tree describes a fixed-link without an "mdio" child node, causing macb_mii_init() to return early without allocating the MDIO bus. Subsequent cleanup code unconditionally dereferences this NULL pointer, leading to a kernel oops on driver unbind or probe error paths.
References
- ubuntu.com/security/CVE-2026-98008 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98008 (opens in a new tab)
- git.kernel.org/stable/c/edb39c7666bb3924da761dfb417db85c1e5d8ad3 (opens in a new tab)
- git.kernel.org/stable/c/f737d999fcb8f276d77b01ea4c2016ee01dad19b (opens in a new tab)
- git.kernel.org/stable/c/38b6be101006d3e7af972999f45d4f1e8250587a (opens in a new tab)
- git.kernel.org/stable/c/5710f6a74f63cbba0e15cd75917234916181c9d4 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-98008 (opens in a new tab)
- git.kernel.org/stable/c/054ad8e66025eb4778d840bef80c270646cebcd2 (opens in a new tab)
- git.kernel.org/stable/c/afa224cabc0132ca414b9141b1a919ca2d318cd0 (opens in a new tab)