CVE-2026-63959: Linux kernel · usb: typec: tcpm/tcpci_maxim: validate header NDO against RX_BYTE_CNT
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in dc17721d42e6d89f63572e63add8306a0e15eb3c : update Linux kernel when convenient.
Data as of 30 Oct 2026, 13:33 UTC
Rated Medium by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- Patch
- Available – fixed in dc17721d42e6d89f63572e63add8306a0e15eb3c, c4ab8e2d4432abb646c5c0687f8dab173da901f9, aa2f716327be1818e1cb156da8a2844804aaec2f +3
Exploitation evidence
Disclosed: evidence found.
CVE published 19 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 30 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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AI-suggested
A fix is available and has been applied in the Linux kernel source code at the specified commits. Users should update their Linux kernel to a version including these fixes to mitigate the vulnerability.
Description
A vulnerability in the Linux kernel's USB Type-C driver (tcpm/tcpci_maxim) allows a broken or malicious port to send a frame with a header indicating up to seven data objects but with fewer actual data objects in the body. This mismatch can cause the kernel to read from uninitialized stack memory. The issue has been fixed in specific commits.
References
- git.kernel.org/stable/c/8a8cd4790b08c9f79ea2250b3bd933fd79f67e56 (opens in a new tab)
- git.kernel.org/stable/c/0af00f1459f5dd757f0d392f8caa38039561ac62 (opens in a new tab)
- git.kernel.org/stable/c/dc17721d42e6d89f63572e63add8306a0e15eb3c (opens in a new tab)
- git.kernel.org/stable/c/9b496e3371c04f0a03b7faa5d2442536d00e3998 (opens in a new tab)
- git.kernel.org/stable/c/c4ab8e2d4432abb646c5c0687f8dab173da901f9 (opens in a new tab)
- git.kernel.org/stable/c/aa2f716327be1818e1cb156da8a2844804aaec2f (opens in a new tab)