# CVE-2026-73644: OpenDJ SASL PLAIN authzid bypassing the proxy ACI scope check

> An authenticated user with PROXIED_AUTH privilege can impersonate any non-root user in OpenDJ, bypassing proxy ACI restrictions.

- **Severity:** Critical 9.6 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N`)
- **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:** 13 Aug 2026
- **Updated:** 18 Aug 2026
- **Also known as:** GHSA-p279-2cqp-84jg

## What is CVE-2026-73644?

CVE-2026-73644 is a critical authentication bypass vulnerability in OpenIdentityPlatform OpenDJ, published on 13 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

OpenDJ is an LDAPv3 compliant directory service. Prior to 5.1.2, the SASL PLAIN authorization identity path in opendj-server-legacy/src/main/java/org/opends/server/extensions/PlainSASLMechanismHandler.java checked the PROXIED_AUTH privilege but did not evaluate the mayProxy proxy ACI scope when an authzid resolved to a different user. Both dn: and u: or bare authzid forms could therefore let an authenticated account holding PROXIED_AUTH assume any resolvable non-root identity outside the identities permitted by its proxy ACI. The fix returns INVALID_CREDENTIALS (49) before password verification when the target authorization identity is not permitted. This issue is fixed in version 5.1.2.

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key), CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2026-73644?

2 open source packages ship an affected version, including org.openidentityplatform.opendj:opendj-server-legacy.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.openidentityplatform.opendj:opendj-server-legacy` | Maven | All versions | 5.1.2 |
| `org.openidentityplatform.opendj:opendj-server-legacy` | Maven | All versions | 5.1.2 |

## How do I fix CVE-2026-73644?

Upgrade org.openidentityplatform.opendj:opendj-server-legacy to 5.1.2 or later.

## Is CVE-2026-73644 being exploited?

There is no known exploitation of CVE-2026-73644 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-73644 and fix it if it is affected.

What it is: CVE-2026-73644 is a critical authentication bypass vulnerability in OpenIdentityPlatform OpenDJ, published on 13 Aug 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-2026-73644 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.openidentityplatform.opendj:opendj-server-legacy (Maven): affected all versions; fixed in 5.1.2
- org.openidentityplatform.opendj:opendj-server-legacy (Maven): affected all versions; fixed in 5.1.2

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-2026-73644/ (Markdown: https://insights.sbomify.com/CVE-2026-73644/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-73644
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-73644
- OSV: https://osv.dev/vulnerability/CVE-2026-73644

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-73644/
Summaries are generated and may contain mistakes; the official description above is the record.