# CVE-2026-16560: 389-ds-base: 389-ds-base: heap-buffer-overflow in rdn_av_swap on quoted multivalued rdn

> A heap-buffer-overflow in 389-ds-base allows attackers to cause denial of service or arbitrary memory writes via crafted DN values.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/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:** No
- **Published:** 22 Jul 2026
- **Updated:** 22 Jul 2026
- **Also known as:** AZL-93072, DEBIAN-CVE-2026-16560, GHSA-cwj4-7fp9-r4jg, UBUNTU-CVE-2026-16560

## What is CVE-2026-16560?

CVE-2026-16560 is a medium-severity memory corruption vulnerability in Red Hat Directory Server 11, published on 22 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A heap-buffer-overflow flaw was found in Directory Server (389-ds-base). When a DN contains a legacy-quoted value, the server won't close the heap allocation allowing another call to refer to the same memory pointer causing a denial of service or an arbitrary memory write operation.

Weakness: CWE-1220 (Insufficient Granularity of Access Control)

## Which versions are affected by CVE-2026-16560?


## How do I fix CVE-2026-16560?

No fix has been published for CVE-2026-16560 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-16560 being exploited?

There is no known exploitation of CVE-2026-16560 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-16560 and fix it if it is affected.

What it is: CVE-2026-16560 is a medium-severity memory corruption vulnerability in Red Hat Directory Server 11, published on 22 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-2026-16560 in the wild and no public exploit code.

Affected product: Red Hat Directory Server 11. 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-2026-16560/ (Markdown: https://insights.sbomify.com/CVE-2026-16560/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-16560
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-16560
- OSV: https://osv.dev/vulnerability/CVE-2026-16560

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-16560/
Summaries are generated and may contain mistakes; the official description above is the record.