CVE-2026-63956: Linux kernel · USB: serial: cypress_m8: fix memory corruption with small endpoint
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 30 Oct 2026, 15:47 UTC
Rated High by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or noneExploitation 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
AI-suggested
A fix has been implemented in the Linux kernel to enforce a minimum interrupt-out endpoint max packet size of eight bytes for the cypress_m8 USB serial driver. Users should apply the updated kernel version containing this fix. No additional mitigations are specified.
Description
A vulnerability in the Linux kernel's USB serial driver for Cypress M8 devices could cause memory corruption or NULL-pointer dereference if a malicious USB device reports an interrupt-out endpoint with a max packet size smaller than eight bytes. This issue has been fixed by ensuring the endpoint size is at least eight bytes.
References
- git.kernel.org/stable/c/4fcb22218f0a7229b7ce3b3952fb644def293fa5 (opens in a new tab)
- git.kernel.org/stable/c/ad3d1628a46134276546d7a12fedf04be9979158 (opens in a new tab)
- git.kernel.org/stable/c/52e18ae0c47c5c89e18fcd8022f287f7cc8802ec (opens in a new tab)
- git.kernel.org/stable/c/4bcaa59f403dbde6328604a500d65ee8d40975d9 (opens in a new tab)
- git.kernel.org/stable/c/1ef25704bd3b625fd151c09feee459479f71ee64 (opens in a new tab)
- git.kernel.org/stable/c/284105c40fc31fff90cdab8a0377aaeb92f87f0e (opens in a new tab)
- git.kernel.org/stable/c/6c13f3bb652bc8665e709ba07122612586aea648 (opens in a new tab)
- git.kernel.org/stable/c/e1a9d791fd66ab2431b9e6f6f835823809869047 (opens in a new tab)