# CVE-2026-21366: Integer Overflow or Wraparound in Data Network Stack & Connectivity

> An integer overflow in the Qualcomm Snapdragon network stack allows memory corruption during packet processing, potentially leading to code execution or denial of service.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Aug 2026
- **Updated:** 5 Aug 2026
- **Also known as:** GHSA-q2v3-gr28-5g2f

## What is CVE-2026-21366?

CVE-2026-21366 is a high-severity vulnerability in Qualcomm Qam8255p Firmware, published on 4 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Memory corruption while processing a packet with a size close to the maximum allowed value.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2026-21366?

It affects 33 products.


Products: Qualcomm Lemans Au Lgit Firmware, Qualcomm Lemansau Firmware, Qualcomm Qam8255p Firmware, Qualcomm Qam8295p Firmware, Qualcomm Qam8620p Firmware, Qualcomm Qamsrv1h Firmware, Qualcomm Qamsrv1m Firmware, Qualcomm Qca6574au Firmware, Qualcomm Qca6595 Firmware, Qualcomm Qca6595au Firmware, Qualcomm Qca6688aq Firmware, Qualcomm Qca6696 Firmware, Qualcomm Qca6698aq Firmware, Qualcomm Qca6797aq Firmware, Qualcomm Qca8695au Firmware, Qualcomm Sa6145p Firmware, Qualcomm Sa6150p Firmware, Qualcomm Sa6155p Firmware, Qualcomm Sa7255p Firmware, Qualcomm Sa7775p Firmware and 13 more.

## How do I fix CVE-2026-21366?

No fix has been published for CVE-2026-21366 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-21366 being exploited?

There is no known exploitation of CVE-2026-21366 in the wild and no public exploit code.

## Other vulnerabilities in Qualcomm Qam8255p Firmware

- [CVE-2026-25278](https://insights.sbomify.com/CVE-2026-25278/): Time-of-check Time-of-use (TOCTOU) Race Condition in Automotive Software platform based on QNX (high 7.8)
- [CVE-2025-47381](https://insights.sbomify.com/CVE-2025-47381/): Use After Free in Automotive Audio (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-21366 and fix it if it is affected.

What it is: CVE-2026-21366 is a high-severity vulnerability in Qualcomm Qam8255p Firmware, published on 4 Aug 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-2026-21366 in the wild and no public exploit code.

Affected product: Qualcomm Qam8255p Firmware. 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-2026-21366/ (Markdown: https://insights.sbomify.com/CVE-2026-21366/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-21366
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-21366
- OSV: https://osv.dev/vulnerability/CVE-2026-21366

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-21366/
Summaries are generated and may contain mistakes; the official description above is the record.