# CVE-2026-58216: Denial of service in Red Hat Enterprise Linux 10

> An authenticated attacker can crash the Samba KDC process by sending malformed ASN.1 data, causing a denial of service.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Jul 2026
- **Updated:** 31 Jul 2026
- **Also known as:** AZL-94169, DEBIAN-CVE-2026-58216, ECHO-6e23-ce84-c852, GHSA-vc9h-gm8g-6j4x, UBUNTU-CVE-2026-58216

## What is CVE-2026-58216?

CVE-2026-58216 is a medium-severity denial of service vulnerability in Red Hat Enterprise Linux 10, published on 30 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An out-of-bounds read flaw was found in Samba's Kerberos Key Distribution Center's (KDC) password change (kpasswd) service. When processing malformed ASN.1-encoded Kerberos password change request, Samba server miscalculates the structure size and attempts to read up to six bytes beyond the end of the allocated buffer. While this out-of-bounds read typically results in a harmless decryption failure, if the read hits unmapped memory, it causes the KDC process to crash. An authenticated attacker can send a specially crafted kpasswd request containing malformed ASN.1 data to trigger the out-of-bounds read, which may cause the KDC process to terminate, resulting in a denial of service.

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

## Which versions are affected by CVE-2026-58216?


## How do I fix CVE-2026-58216?

Apply the vendor's patch.

## Is CVE-2026-58216 being exploited?

There is no known exploitation of CVE-2026-58216 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-58216 and fix it if it is affected.

What it is: CVE-2026-58216 is a medium-severity denial of service vulnerability in Red Hat Enterprise Linux 10, published on 30 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-58216 in the wild and no public exploit code.

Affected product: Red Hat Enterprise Linux 10. 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-2026-58216/ (Markdown: https://insights.sbomify.com/CVE-2026-58216/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-58216
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-58216
- OSV: https://osv.dev/vulnerability/CVE-2026-58216

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-58216/
Summaries are generated and may contain mistakes; the official description above is the record.