# CVE-2026-90175: smb: server: fix leak of ksmbd_ipc_login_request_ext() returned buffer

> A memory leak in the Linux kernel's ksmbd SMB server allows local attackers to exhaust kernel memory, causing denial of service.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-102453, BELL-CVE-2026-90175, DEBIAN-CVE-2026-90175, GHSA-jxh3-3qm5-qh2j, UBUNTU-CVE-2026-90175

## What is CVE-2026-90175?

CVE-2026-90175 is a memory corruption vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

smb: server: fix leak of ksmbd_ipc_login_request_ext() returned buffer

Free it unconditionally after ksmbd_alloc_user() calls.

kmemleak splat:
  unreferenced object 0xffff888103b83540 (size 192):
    comm "pool-0", pid 16970, jiffies 4377290937
    hex dump (first 32 bytes):
      00 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00  ................
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    backtrace (crc 408ccc66):
      __kvmalloc_node_noprof+0x730/0x920
      handle_generic_event+0xec/0x1a0 [ksmbd]
      genl_family_rcv_msg_doit+0xe0/0x130
      genl_rcv_msg+0x181/0x290
      netlink_rcv_skb+0x4f/0x100
      genl_rcv+0x28/0x40
      netlink_unicast+0x1e6/0x2c0
      netlink_sendmsg+0x20a/0x450
      ____sys_sendmsg+0x2e8/0x310
      ___sys_sendmsg+0x78/0xc0
      __sys_sendmsg+0x63/0xc0
      do_syscall_64+0xa1/0x670
      entry_SYSCALL_64_after_hwframe+0x76/0x7e

## Which versions are affected by CVE-2026-90175?


## How do I fix CVE-2026-90175?

Apply the vendor's patch.

## Is CVE-2026-90175 being exploited?

There is no known exploitation of CVE-2026-90175 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90175 and fix it if it is affected.

What it is: CVE-2026-90175 is a memory corruption vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-90175 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-90175/ (Markdown: https://insights.sbomify.com/CVE-2026-90175/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90175
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90175
- OSV: https://osv.dev/vulnerability/CVE-2026-90175

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90175/
Summaries are generated and may contain mistakes; the official description above is the record.