CVE-2026-63958: Linux kernel · usb: typec: ucsi: validate connector number in ucsi_connector_change()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.0 High · fixed in 6.8.0-1066.69~22.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1066.69~22.04.1, 6.8.0-1070.78~22.04.1, 6.8.0-1068.75~22.04.1 +36
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation 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
An official patch is available and should be applied to affected Linux kernel versions to prevent out-of-bounds array access in the ucsi_connector_change() function. Users should update to fixed kernel versions as provided by their distribution vendors. No additional mitigation is required beyond applying the patch.
Description
A vulnerability in the Linux kernel's USB Type-C UCSI driver was resolved by validating connector numbers in the ucsi_connector_change() function. The flaw allowed a buggy or malicious Platform Policy Manager (PPM) to use an out-of-bounds connector number, potentially causing memory corruption by indexing beyond the array bounds. This issue affects multiple Linux kernel versions including various linux-azure builds. A patch is available to reject invalid connector numbers before dereferencing the array.
References
- nvd.nist.gov/vuln/detail/CVE-2026-63958 (opens in a new tab)
- git.kernel.org/stable/c/0edd1e21587b0483c7ceb993b9fb9668bbef7433 (opens in a new tab)
- git.kernel.org/stable/c/156b6f0aec6108909b0c4aedc78865b12766b347 (opens in a new tab)
- git.kernel.org/stable/c/288a81a8507052bcfbf884d39a463c44c42c5fd9 (opens in a new tab)
- git.kernel.org/stable/c/5af2719b460ab904c504fc069d1dd2a3aa2b22b0 (opens in a new tab)
- git.kernel.org/stable/c/bd24d92af4ae021b6209f28e9a57e1bf2260d4fd (opens in a new tab)
- git.kernel.org/stable/c/cea949203faef9cb783adc7b978cce056271e057 (opens in a new tab)
- ubuntu.com/security/CVE-2026-63958 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-63958 (opens in a new tab)
- git.kernel.org/linus/288a81a8507052bcfbf884d39a463c44c42c5fd9 (opens in a new tab)
- ubuntu.com/security/notices/USN-8593-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8603-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8618-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8663-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8664-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8903-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8905-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8906-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8904-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8903-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8905-2 (opens in a new tab)