CVE-2026-63898: Linux kernel · USB: serial: mct_u232: fix memory corruption with small endpoint
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 30 Oct 2026, 15:35 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 prevent increasing the maximum transfer size beyond the device's actual endpoint size. Users should update to the fixed Linux kernel version once available to remediate this issue.
Description
A memory corruption vulnerability in the Linux kernel's USB serial driver mct_u232 has been fixed. The issue arises because the driver overrides the maximum transfer size for a device that only accepts 16-byte packets on a 32-byte bulk-out endpoint. This can lead to slab corruption if a malicious device reports a smaller endpoint max packet size than expected.
References
- git.kernel.org/stable/c/94edbbc5fe00d03cfe1d4e690d7d2cd36317a935 (opens in a new tab)
- git.kernel.org/stable/c/bd2ddb3fe9052ad8703593bbec26ecc7ca92869e (opens in a new tab)
- git.kernel.org/stable/c/39e295a91e80f3b91f61c7ada2bde434dcaba20d (opens in a new tab)
- git.kernel.org/stable/c/90dbad14b109e5fdfb4934ff61e561d11ba3742d (opens in a new tab)
- git.kernel.org/stable/c/6cb48f8890f9b2051d7c34823057296a536a31c5 (opens in a new tab)
- git.kernel.org/stable/c/d8fdf33d6fcfb90cbec26299baf2352c84b2d768 (opens in a new tab)
- git.kernel.org/stable/c/57f332af1745014cd7e40414814ffaa6bc7d3b5b (opens in a new tab)
- git.kernel.org/stable/c/915b36d701950503c4ea0f6e314b10868e59fce3 (opens in a new tab)