---
id: "CVE-2026-99273"
page: "https://infrastack.ai/live/CVE-2026-99273"
kind: "vulnerability"
aliases: ["CVE-2026-99273"]
title: "Linux kernel ksmbd: stream info writes past its response buffer"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["ksmbd", "linux-kernel", "package", "smb-server"]
not_affected_if: ["ksmbd-disabled"]
published_at: "2026-11-07T14:17:02+00:00"
first_seen_at: "2026-11-07T14:47:40+00:00"
updated_at: "2026-11-07T14:49:56+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-99273", "first_seen_at": "2026-11-07T14:47:40+00:00"}]
exploit_sources: []
---

# Linux kernel ksmbd: stream info writes past its response buffer

Link for people: https://infrastack.ai/live/CVE-2026-99273 (this .md is for agents)

The ksmbd SMB file server in the Linux kernel writes a UTF-16 terminator two bytes past the end of a small response buffer when stream info exactly fills it. The sources do not state what an attacker can do with that out-of-bounds write.

_Summary, check and fix written by a model from the sources; labelled as such._

## Timeline

- 2026-11-07T14:47:40+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-99273

## From the sources

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: reserve space for the UTF-16 terminator in stream info

smb_strtoUTF16() always writes a terminating zero UTF-16 unit after the
converted characters, but get_file_stream_info() budgets only
sizeof(struct smb2_file_stream_info) + streamlen * 2 for a stream entry
and sizeof(struct smb2_file_stream_info) + 7 * 2 for the trailing
"::$DATA" entry. When an entry exactly fills the 448-byte small response
buffer, the terminator is written two bytes past the allocation.

Reserve one extra UTF-16 unit in both budget checks. The terminator is
not part of the wire format, so the reported lengths are unchanged.

---

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