# CVE-2026-18796: QSPI flash encryption side-channel leakage

> Attackers can exploit side-channel leakage in QSPI flash encryption to compromise confidentiality and integrity of externally stored code on nRF5340 devices.

- **Severity:** Medium 6.8 (`CVSS:4.0/AV:P/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Sep 2026
- **Updated:** 10 Sep 2026
- **Also known as:** GHSA-q9vx-6fw9-4mv8

## What is CVE-2026-18796?

CVE-2026-18796 is a medium-severity vulnerability in Nordic Semiconductor ASA nRF5340, published on 7 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Any application that
     uses external QSPI flash for encrypted XIP on nRF5340 and relies on that
     encryption for confidentiality and/or integrity of the externally stored
     code. No specific nRF Connect SDK version is the root cause; the weakness
     is in the on-the-fly decryption scheme.

Weakness: CWE-1342 (Information Exposure through Microarchitectural State after Transient Execution)

## Which versions are affected by CVE-2026-18796?


## How do I fix CVE-2026-18796?

No fix has been published for CVE-2026-18796 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-18796 being exploited?

There is no known exploitation of CVE-2026-18796 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-18796 and fix it if it is affected.

What it is: CVE-2026-18796 is a medium-severity vulnerability in Nordic Semiconductor ASA nRF5340, published on 7 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-2026-18796 in the wild and no public exploit code.

Affected product: Nordic Semiconductor ASA nRF5340. 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-2026-18796/ (Markdown: https://insights.sbomify.com/CVE-2026-18796/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18796
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18796
- OSV: https://osv.dev/vulnerability/CVE-2026-18796

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-18796/
Summaries are generated and may contain mistakes; the official description above is the record.