# CVE-2026-11793: 389-ds-base: 389-ds-base: stack buffer overflow in checkprefix() algorithm id parsing

> An attacker with Directory Manager privileges can crash the LDAP server via a stack buffer overflow in algorithm ID parsing.

- **Severity:** Medium 4.9 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Jun 2026
- **Updated:** 7 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-11793, GHSA-v6v5-66j3-444p, UBUNTU-CVE-2026-11793

## What is CVE-2026-11793?

CVE-2026-11793 is a medium-severity memory corruption vulnerability in Red Hat Directory Server 11, published on 9 Jun 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

A stack buffer overflow flaw was found in 389 Directory Server. The checkPrefix() function in pw.c copies an attacker-controlled algorithm ID into a 256-byte stack buffer without bounds checking when parsing reversible-encrypted attribute values. An attacker with Directory Manager privileges can crash the LDAP server by storing a crafted credential with an oversized algorithm ID. FORTIFY_SOURCE mitigates this to denial of service only.

Weakness: CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2026-11793?

It affects 1 product.


Products: Redhat 389 Directory Server.

## How do I fix CVE-2026-11793?

Apply the vendor's patch.

## Is CVE-2026-11793 being exploited?

There is no known exploitation of CVE-2026-11793 in the wild and no public exploit code.

## Other vulnerabilities in Red Hat Directory Server 11

- [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-2026-11793 and fix it if it is affected.

What it is: CVE-2026-11793 is a medium-severity memory corruption vulnerability in Red Hat Directory Server 11, published on 9 Jun 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-11793 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-2026-11793/ (Markdown: https://insights.sbomify.com/CVE-2026-11793/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-11793
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-11793
- OSV: https://osv.dev/vulnerability/CVE-2026-11793

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-11793/
Summaries are generated and may contain mistakes; the official description above is the record.