CVE-2026-63962: Linux kernel · usb: typec: tcpm: bound altmode_desc[] per iteration in svdm_consume_modes()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.4 High · fixed in 7.0.0-1014.14~24.04.1 : patch Linux kernel soon.
Data as of 28 Oct 2026, 12:15 UTC
- Patch
- Available – fixed in 7.0.0-1014.14~24.04.1, 7.0.0-1013.13~24.04.1, 7.0.0-1011.11~24.04.1 +12
CVSS:4.0/AV:P/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 19 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.
Patches and advisories
- 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)
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 and should be applied by upgrading affected Linux kernel versions to 7.0.0-28.28~24.04.1 or later as provided by the vendor. The Ubuntu security advisory USN-8593-1 confirms the fix and recommends updating to the fixed kernel releases. No additional mitigation is required beyond applying the official kernel update.
Description
CVE-2026-63962 is a vulnerability in the Linux kernel's USB Type-C Port Manager (tcpm) subsystem where the function svdm_consume_modes() improperly bounds checks an array during processing of DisplayPort alternate modes. This flaw allows a malicious or broken USB Type-C partner device to cause out-of-bounds writes by sending unsolicited Discover Modes ACK messages with excessive data. The issue is fixed by moving the bounds check inside the processing loop to prevent array overflow regardless of input. Multiple Linux kernel versions prior to 7.0.0-28.28~24.04.1 and related builds are affected.
References
- ubuntu.com/security/CVE-2026-63962 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-63962 (opens in a new tab)
- git.kernel.org/linus/3389c149c68c3fea61910ad5d34f7bf3bff44e32 (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)