CVE-2026-93821: Linux kernel · PCI: altera: Protect root bus removal with rescan lock
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 14:05 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 24 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 addresses the vulnerability by properly holding the pci_rescan_remove_lock during root bus removal. Users should update to a patched Linux kernel version that includes this fix. Since this is not a cloud service, remediation requires applying the vendor's kernel updates.
Description
A vulnerability in the Linux kernel related to the PCI Altera driver has been resolved. The issue involved improper locking during root bus removal, which could lead to race conditions with concurrent rescan or hotplug operations. These races might cause use-after-free errors or system crashes. The vulnerability affects specific Linux kernel versions listed and has been fixed by holding the pci_rescan_remove_lock during the removal process.
References
- ubuntu.com/security/CVE-2026-93821 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-93821 (opens in a new tab)
- git.kernel.org/stable/c/7cbb8f2750d91e64caff89e164ac8280bb80bedc (opens in a new tab)
- git.kernel.org/stable/c/c0cd65906e5f7e293ef2568c9524cc0a918333c3 (opens in a new tab)
- git.kernel.org/stable/c/a8759c8ac48c0419f5899e95a6ffc611b07c965b (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-93821 (opens in a new tab)
- git.kernel.org/stable/c/442b7f2a093b4a75f8963aaa7cbb2b8df35a6ac3 (opens in a new tab)
- git.kernel.org/stable/c/4b69c63cc247fc0f499fbd11076fee9c2a6e6fd7 (opens in a new tab)
- git.kernel.org/stable/c/cf9d84d1b6a7c3f3780c043df220a7e9e38137eb (opens in a new tab)
- git.kernel.org/stable/c/fc462f1bdeaea9789928cbfdf5e069ee559c7642 (opens in a new tab)