# CVE-2026-68098: ksmbd: bound DACL dedup walk to copied ACEs

> An out-of-bounds read in the Linux kernel ksmbd module allows attackers to inspect invalid memory or cause a crash during DACL processing.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 10 Aug 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-68098, DEBIAN-CVE-2026-68098, GHSA-v5fh-ff84-cfpv, UBUNTU-CVE-2026-68098

## What is CVE-2026-68098?

CVE-2026-68098 is a high-severity memory corruption vulnerability in Linux, published on 10 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

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

ksmbd: bound DACL dedup walk to copied ACEs

set_ntacl_dacl() can stop copying ACEs before consuming the full input
DACL when size accounting overflows.

When that happens, num_aces reflects only the ACEs that were actually
copied into the output DACL, but set_posix_acl_entries_dacl() still
receives nt_num_aces and uses it to walk the existing ACE array during
dedup.

That makes the dedup walk scan past the copied ACE array and inspect
buffer tail that does not contain valid ACEs.

Split the two meanings currently carried by the NT ACE count. Pass the
number of copied NT ACEs to bound the dedup walk, and preserve the
original "input DACL had NT ACEs" state separately for the
Everyone/default ACL fallback.

This keeps the dedup walk aligned with the ACEs that are actually
present in the rebuilt DACL.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-68098?


## How do I fix CVE-2026-68098?

Apply the vendor's patch.

## Is CVE-2026-68098 being exploited?

There is no known exploitation of CVE-2026-68098 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68098 and fix it if it is affected.

What it is: CVE-2026-68098 is a high-severity memory corruption vulnerability in Linux, published on 10 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-68098 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-2026-68098/ (Markdown: https://insights.sbomify.com/CVE-2026-68098/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68098
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68098
- OSV: https://osv.dev/vulnerability/CVE-2026-68098

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68098/
Summaries are generated and may contain mistakes; the official description above is the record.