# CVE-2026-10659: NULL pointer dereference in Zephyr Dhara FTL disk driver on flash read error during journal resume

> A NULL pointer dereference in the Zephyr Dhara FTL driver causes a kernel crash during disk initialization if a flash read error occurs.

- **Severity:** Medium 4.7 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **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:** No
- **Published:** 7 Jul 2026
- **Updated:** 31 Aug 2026
- **Also known as:** GHSA-q28v-3729-f82g

## What is CVE-2026-10659?

CVE-2026-10659 is a medium-severity vulnerability in Zephyrproject Zephyr, published on 7 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The Dhara flash translation layer disk driver (drivers/disk/ftl_dhara.c) implemented the dhara_nand_ callbacks so that, on a flash error, the error code was written unconditionally through the caller-supplied dhara_error_t err pointer (e.g. *err = DHARA_E_ECC in dhara_nand_read, and similar in dhara_nand_erase/prog/copy).

The upstream Dhara library calls these callbacks with err == NULL along its journal-resume binary search: find_last_checkblock() invokes find_checkblock(j, mid, &found, NULL), which forwards the NULL pointer into dhara_nand_read(). This path runs during disk_ftl_access_init() -> dhara_map_resume() whenever the FTL disk is mounted/initialised.

If a flash read error (uncorrectable ECC, bad block, controller error) occurs on one of the probed checkpoint pages, the driver dereferences and writes to NULL, faulting the kernel (denial of service). The trigger is conditioned on the NAND medium content/health, which can be influenced by media wear, induced faults, or a corrupted/crafted on-flash image.

The fix routes all error assignments through the library's NULL-safe dhara_set_error() helper. Affects Zephyr v4.4.0, where the driver was introduced.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-10659?

It affects 1 product.


Products: Zephyrproject Zephyr.

## How do I fix CVE-2026-10659?

No fix has been published for CVE-2026-10659 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-10659 being exploited?

There is no known exploitation of CVE-2026-10659 in the wild and no public exploit code.

## Other vulnerabilities in Zephyrproject Zephyr

- [CVE-2026-5067](https://insights.sbomify.com/CVE-2026-5067/): Out-of-bounds read/write in HTTP WebSocket upgrade via non-null-terminated Sec-WebSocket-Key (critical 9.8)
- [CVE-2022-3806](https://insights.sbomify.com/CVE-2022-3806/): Bluetooth HCI Error Handling Double Free (critical 9.8)
- [CVE-2017-14199](https://insights.sbomify.com/CVE-2017-14199/): Memory corruption in getaddrinfo (critical 9.8)
- [CVE-2018-1000800](https://insights.sbomify.com/CVE-2018-1000800/): Null dereference in n/a (critical 9.8)
- [CVE-2021-3329](https://insights.sbomify.com/CVE-2021-3329/): DOS: Incorrect handling of the initial HCI ACL_MTU handshake packet leads to crash of bluetooth host layer (critical 9.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-10659 and fix it if it is affected.

What it is: CVE-2026-10659 is a medium-severity vulnerability in Zephyrproject Zephyr, published on 7 Jul 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-2026-10659 in the wild and no public exploit code.

Affected product: Zephyrproject Zephyr. 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-2026-10659/ (Markdown: https://insights.sbomify.com/CVE-2026-10659/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-10659
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-10659
- OSV: https://osv.dev/vulnerability/CVE-2026-10659

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-10659/
Summaries are generated and may contain mistakes; the official description above is the record.