Out-of-bounds write in Linux kernel - CVE-2026-99273

Vulnerability details

The vulnerability allows a remote user to corrupt kernel memory, potentially causing a denial of service.

The vulnerability exists due to an out-of-bounds write in the Linux kernel ksmbd get_file_stream_info() function when generating stream information without reserving space for a terminating UTF-16 unit. A remote user can trigger processing of a stream entry that exactly fills the 448-byte response buffer to cause a two-byte write past the allocation, potentially causing a denial of service.

Affected software

How to mitigate CVE-2026-99273

External References

• https://git.kernel.org/stable/c/06a751809ebd33e95b05bf733697318a17a4872b
• https://git.kernel.org/stable/c/0e64f89563164719ceb1aa33f2a8bfd6391fa340
• https://git.kernel.org/stable/c/a025c4991a7d83edc4dd339e3ea86d8ff6226eca

Related Security Bulletins

• Out-of-bounds write in Linux kernel smb server