# CVE-2026-14940: 389-ds-base: 389-ds-base: heap-buffer-overflow in dn normalization via quoted multivalued rdn

> An unauthenticated remote attacker can cause a heap-buffer-overflow and denial of service in 389 Directory Server by sending a crafted LDAP search request.

- **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:** 7 Jul 2026
- **Updated:** 7 Jul 2026
- **Also known as:** AZL-92189, DEBIAN-CVE-2026-14940, GHSA-868f-j5w9-5jgm, UBUNTU-CVE-2026-14940

## What is CVE-2026-14940?

CVE-2026-14940 is a medium-severity memory corruption vulnerability in Redhat Enterprise Linux, published on 7 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 389 Directory Server (389-ds-base). When
normalizing a Distinguished Name (DN) that contains a legacy-quoted value encoding a
multivalued nested Relative Distinguished Name (RDN), the server can write past the
end of a heap allocation while sorting RDN attribute-value pairs. An unauthenticated
remote attacker can trigger this condition by sending an LDAP operation whose DN
reaches the DN normalization routine, such as a search with a crafted base DN. This
can corrupt heap memory and may cause denial of service.

Weakness: CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2026-14940?

It affects 3 products.


Products: Redhat 389 Directory Server, Redhat Directory Server, Redhat Enterprise Linux.

## How do I fix CVE-2026-14940?

No fix has been published for CVE-2026-14940 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-14940 being exploited?

There is no known exploitation of CVE-2026-14940 in the wild and no public exploit code.

## Other vulnerabilities in Redhat Enterprise Linux

- [CVE-2026-11770](https://insights.sbomify.com/CVE-2026-11770/): 389-ds-base: 389-ds-base: pre-auth ldap filter injection in cleanallruv status check (high 7.5)
- [CVE-2026-15722](https://insights.sbomify.com/CVE-2026-15722/): Memory corruption in Red Hat Directory Server 11.5 E4S for RHEL 8 (high 7.5)
- [CVE-2026-9064](https://insights.sbomify.com/CVE-2026-9064/): Denial of service in Red Hat Directory Server 11.5 E4S for RHEL 8 (high 7.5)
- [CVE-2010-2222](https://insights.sbomify.com/CVE-2010-2222/): Null dereference in Red Hat Directory Server (high 7.5)
- [CVE-2026-11611](https://insights.sbomify.com/CVE-2026-11611/): 389-ds-base: 389-ds-base: content sync plugin unbounded queue growth and race conditions (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-14940 and fix it if it is affected.

What it is: CVE-2026-14940 is a medium-severity memory corruption vulnerability in Redhat Enterprise Linux, published on 7 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-2026-14940 in the wild and no public exploit code.

Affected product: Redhat Enterprise Linux. 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-2026-14940/ (Markdown: https://insights.sbomify.com/CVE-2026-14940/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-14940
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-14940
- OSV: https://osv.dev/vulnerability/CVE-2026-14940

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-14940/
Summaries are generated and may contain mistakes; the official description above is the record.