# CVE-2026-12665: IBM MQ Buffer Overflow

> Remote attackers can execute arbitrary code via a stack buffer overflow in IBM MQ during TLS certificate processing.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Oct 2026
- **Updated:** 20 Oct 2026
- **Also known as:** GHSA-2ph8-cjp5-hwrv

## What is CVE-2026-12665?

CVE-2026-12665 is a high-severity memory corruption vulnerability in IBM MQ Advanced container images, published on 19 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

IBM MQ could allow a remote attacker to execute arbitrary code due to a stack buffer overflow when processing TLS certificates with malformed distinguished names during channel connection establishment.

Weakness: CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2026-12665?

It affects 2 products.


Products: Ibm Mq Operator, Ibm Supplied Mq Advanced Container Images.

## How do I fix CVE-2026-12665?

No fix has been published for CVE-2026-12665 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-12665 being exploited?

There is no known exploitation of CVE-2026-12665 in the wild and no public exploit code.

## Other vulnerabilities in IBM MQ Advanced container images

- [CVE-2026-10572](https://insights.sbomify.com/CVE-2026-10572/): IBM MQ Buffer Overflow (high 8.8)
- [CVE-2026-10574](https://insights.sbomify.com/CVE-2026-10574/): IBM MQ Buffer Overflow (high 8.8)
- [CVE-2026-10743](https://insights.sbomify.com/CVE-2026-10743/): IBM MQ Race Condition (high 8.8)
- [CVE-2024-39742](https://insights.sbomify.com/CVE-2024-39742/): IBM MQ Container authentication bypass (high 8.1)
- [CVE-2026-12148](https://insights.sbomify.com/CVE-2026-12148/): IBM MQ Deserialization of Untrusted Data (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-12665 and fix it if it is affected.

What it is: CVE-2026-12665 is a high-severity memory corruption vulnerability in IBM MQ Advanced container images, published on 19 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-12665 in the wild and no public exploit code.

Affected product: IBM MQ Advanced container images. 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-2026-12665/ (Markdown: https://insights.sbomify.com/CVE-2026-12665/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-12665
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-12665
- OSV: https://osv.dev/vulnerability/CVE-2026-12665

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-12665/
Summaries are generated and may contain mistakes; the official description above is the record.