CVE-2026-64191: Linux kernel · i2c: stub: Reject I2C block transfers with invalid length
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% 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 +43
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 20 Jul 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 the vulnerability by rejecting I2C block transfers with invalid lengths. Users should update their Linux kernel to a version including this fix. Since this is a kernel module vulnerability, applying the official kernel update and rebooting the system will mitigate the issue.
Description
A vulnerability in the Linux kernel's i2c-stub driver allows local users with access to /dev/i2c-* to cause out-of-bounds memory access by issuing I2C block transfers with invalid lengths. This occurs because the driver does not properly validate the transfer length against the maximum allowed block size, leading to potential memory corruption. The issue affects development/test kernel modules and has been fixed by rejecting invalid transfer lengths.
References
- nvd.nist.gov/vuln/detail/CVE-2026-64191 (opens in a new tab)
- git.kernel.org/stable/c/0526931b16e5a118d367b7bfce7d797e63f7ac69 (opens in a new tab)
- git.kernel.org/stable/c/1c4ffe6b4f04365485ed58d64c9bb86b46fc9037 (opens in a new tab)
- git.kernel.org/stable/c/21e87f336ac6303fed54a69b1d0d79a23b25c8d0 (opens in a new tab)
- git.kernel.org/stable/c/3fd225f3e4cd67ec8ddab1afed9da03c7c43537c (opens in a new tab)
- git.kernel.org/stable/c/4bd8635f28c135a08aac6badcd7d9b5cdb34335f (opens in a new tab)
- git.kernel.org/stable/c/5f4d2bd028ebb6e4c09a9d64842546022321d4a7 (opens in a new tab)
- git.kernel.org/stable/c/6036b5067a8199ba7a2dc7b377d4b9dd276d5f9e (opens in a new tab)
- git.kernel.org/stable/c/7e9072dbd5f2f17934751873450d2c22080ead80 (opens in a new tab)
- ubuntu.com/security/CVE-2026-64191 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64191 (opens in a new tab)
- git.kernel.org/linus/6036b5067a8199ba7a2dc7b377d4b9dd276d5f9e (opens in a new tab)
- msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-64191.json (opens in a new tab)
- support.microsoft.com/lifecycle (opens in a new tab)
- first.org/cvss (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8781-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (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-8875-2 (opens in a new tab)