# CVE-2026-55654: Memory corruption in Red Hat Enterprise Linux 10

> Remote attackers can cause SSH service crashes via heap out-of-bounds read in GSSAPI cleanup, requiring GSSAPI and Kerberos configuration.

- **Severity:** Low 3.7 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 23 Jun 2026
- **Updated:** 24 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-55654, GHSA-5mx2-7g4j-9m39, UBUNTU-CVE-2026-55654

## What is CVE-2026-55654?

CVE-2026-55654 is a low-severity memory corruption vulnerability in OpenSSH, published on 23 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw was found in OpenSSH. This vulnerability, a heap out-of-bounds read, occurs during the cleanup of GSSAPI (Generic Security Service Application Programming Interface) indicators when a trailing NULL termination is missing in the auth-indicators array. A remote attacker, under specific configurations involving GSSAPI authentication and a Kerberos environment, could exploit this to cause the SSH authentication path to crash or abort. This leads to a denial of service (DoS), impacting the availability of the SSH service.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-55654?

It affects 3 products.


Products: OpenSSH, Redhat Enterprise Linux, Redhat Hardened Images.

## How do I fix CVE-2026-55654?

Apply the vendor's patch.

## Is CVE-2026-55654 being exploited?

There is no known exploitation of CVE-2026-55654 in the wild and no public exploit code.

## Other vulnerabilities in OpenSSH

- [CVE-2003-0786](https://insights.sbomify.com/CVE-2003-0786/): Auth bypass in n/a (critical 10.0)
- [CVE-2003-0693](https://insights.sbomify.com/CVE-2003-0693/): Memory corruption in n/a (critical 10.0)
- [CVE-2002-0640](https://insights.sbomify.com/CVE-2002-0640/): Memory corruption in n/a (critical 10.0)
- [CVE-2001-0144](https://insights.sbomify.com/CVE-2001-0144/): Integer overflow in n/a (critical 10.0)
- [CVE-2000-0999](https://insights.sbomify.com/CVE-2000-0999/): Memory corruption in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55654 and fix it if it is affected.

What it is: CVE-2026-55654 is a low-severity memory corruption vulnerability in OpenSSH, published on 23 Jun 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-2026-55654 in the wild and no public exploit code.

Affected product: OpenSSH. 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-2026-55654/ (Markdown: https://insights.sbomify.com/CVE-2026-55654/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55654
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55654
- OSV: https://osv.dev/vulnerability/CVE-2026-55654

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55654/
Summaries are generated and may contain mistakes; the official description above is the record.