# CVE-2026-4942: IBM i is Affected by Algorithm Downgrade in Transport Layer Security []

> Remote attackers can downgrade TLS protocol versions on IBM i systems, bypassing security configurations intended to disable weaker protocols.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 17 Jul 2026
- **Updated:** 20 Jul 2026
- **Also known as:** GHSA-cffx-9q2g-r6hp

## What is CVE-2026-4942?

CVE-2026-4942 is a medium-severity vulnerability in Ibm I, published on 17 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to send a specifically crafted message and downgrade the Transport Layer Security (TLS) protocol to a version disabled in the server configuration.

Weakness: CWE-757 (Selection of Less-Secure Algorithm During Negotiation)

## Which versions are affected by CVE-2026-4942?

It affects 1 product.


Products: Ibm I.

## How do I fix CVE-2026-4942?

No fix has been published for CVE-2026-4942 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-4942 being exploited?

There is no known exploitation of CVE-2026-4942 in the wild and no public exploit code.

## Other vulnerabilities in Ibm I

- [CVE-2026-96119](https://insights.sbomify.com/CVE-2026-96119/): IBM i is Affected By An Improper Control of Code Generation Vulnerability in HTTP Server Administration GUI (critical 9.9)
- [CVE-2026-16860](https://insights.sbomify.com/CVE-2026-16860/): IBM i is Affected By Remote Code Execution Vulnerability [] (critical 9.9)
- [CVE-2026-17083](https://insights.sbomify.com/CVE-2026-17083/): IBM i is Affected By Multiple Vulnerabilities in the Debug Server (critical 9.8)
- [CVE-2026-17218](https://insights.sbomify.com/CVE-2026-17218/): IBM i is Affected By Remote Code Execution Vulnerability in Line Printer Daemon [] (critical 9.8)
- [CVE-2026-17276](https://insights.sbomify.com/CVE-2026-17276/): IBM i is Affected By Multiple Vulnerabilities in Navigator for i (critical 9.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-4942 and fix it if it is affected.

What it is: CVE-2026-4942 is a medium-severity vulnerability in Ibm I, published on 17 Jul 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-2026-4942 in the wild and no public exploit code.

Affected product: Ibm I. 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-2026-4942/ (Markdown: https://insights.sbomify.com/CVE-2026-4942/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-4942
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-4942
- OSV: https://osv.dev/vulnerability/CVE-2026-4942

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-4942/
Summaries are generated and may contain mistakes; the official description above is the record.