CVE-2026-72238: Linux kernel · x86/boot: Validate console=uart8250 baud rate to fix early boot hang
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 5.15.0-1117.124~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:47 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +41
Exploitation evidence
Disclosed: evidence found.
CVE published 15 Aug 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
Upgrade to a fixed release listed under Affected software.
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 patch is available that fixes this vulnerability by validating the baud rate and falling back to a default value when the baud rate is zero or invalid. Users should apply the official Linux kernel updates that address this issue to prevent early boot hangs.
Description
A vulnerability in the Linux kernel's x86 boot code could cause an early system hang during boot if the console=uart8250 baud rate parameter is empty, zero, invalid, or overflows to zero. This happens due to a division by zero error in early_serial_init(). The issue has been fixed by validating the baud rate and falling back to a default value to prevent the hang.
References
- nvd.nist.gov/vuln/detail/CVE-2026-72238 (opens in a new tab)
- git.kernel.org/stable/c/24fbed0a2a45f5f379ef2b53bd2abe58be1142ad (opens in a new tab)
- git.kernel.org/stable/c/4dad7e870c7e5178f71b5e1e4f67934b9e8cc207 (opens in a new tab)
- git.kernel.org/stable/c/9a77a7639dfdc3eca417cd37620ce64da79c80c4 (opens in a new tab)
- git.kernel.org/stable/c/b4d05032e9af7137eab8f3af2855073f896ca843 (opens in a new tab)
- git.kernel.org/stable/c/c1a276a731d02cbb728d0530f327a68728f2d8b0 (opens in a new tab)
- git.kernel.org/stable/c/efa96a22613b86e05cd81229ce0be411c1a4a79a (opens in a new tab)
- git.kernel.org/stable/c/f7c67c97b37c11f2a95c204092fb8159f2779e8f (opens in a new tab)
- git.kernel.org/stable/c/ffa0aa5b625fe0bed7463ac613f8b06676ff4542 (opens in a new tab)
- ubuntu.com/security/CVE-2026-72238 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-72238 (opens in a new tab)
- git.kernel.org/linus/ffa0aa5b625fe0bed7463ac613f8b06676ff4542 (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)