# CVE-2026-98169: smb: client: fix potential OOB read in smb3_enum_snapshots()

> A local attacker can trigger an out-of-bounds read in the Linux kernel SMB client to leak adjacent slab memory to userspace.

- **Severity:** High 7.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 6 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-105996, BELL-CVE-2026-98169, DEBIAN-CVE-2026-98169, GHSA-2c6m-5vjc-xqc6, UBUNTU-CVE-2026-98169

## What is CVE-2026-98169?

CVE-2026-98169 is a high-severity vulnerability in Linux, published on 6 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

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

smb: client: fix potential OOB read in smb3_enum_snapshots()

If snapshot_array_size is smaller than GMT_TOKEN_SIZE,
smb3_enum_snapshots() sets ret_data_len to
sizeof(struct smb_snapshot_array) without verifying the actual length
of the server's reply.

Because SMB2_ioctl() places no lower bound on the server-supplied
OutputCount and allocates retbuf to exactly that length, a short reply
results in ret_data_len exceeding the size of retbuf. The subsequent
copy_to_user() then reads past the end of retbuf, leaking adjacent slab
memory to userspace.  The subsequent clamp check is ineffective as it
only reduces ret_data_len.

Fix this by rejecting replies shorter than
sizeof(struct smb_snapshot_array) with -EIO. Note that the bound is set
to the 12-byte struct size rather than the 16-byte
MIN_SNAPSHOT_ARRAY_SIZE defined in MS-SMB2 3.3.5.15.1, because 12 bytes
is exactly what copy_to_user() attempts to read.

## Which versions are affected by CVE-2026-98169?


## How do I fix CVE-2026-98169?

Apply the vendor's patch.

## Is CVE-2026-98169 being exploited?

There is no known exploitation of CVE-2026-98169 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98169 and fix it if it is affected.

What it is: CVE-2026-98169 is a high-severity vulnerability in Linux, published on 6 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-98169 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-2026-98169/ (Markdown: https://insights.sbomify.com/CVE-2026-98169/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98169
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98169
- OSV: https://osv.dev/vulnerability/CVE-2026-98169

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98169/
Summaries are generated and may contain mistakes; the official description above is the record.