---
title: "CVE-2026-73644: OpenDJ SASL PLAIN authzid bypassing the proxy ACI scope check"
url: https://erroneo.us/security/cve/CVE-2026-73644/
description: "CVE-2026-73644 (org.openidentityplatform.opendj:opendj-server-legacy (Maven)): OpenDJ is an LDAPv3 compliant directory service. Prior to 5.1.2, the SASL…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-08-13
date_modified: 2026-08-18
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-73644"
kev: false
cvss: 9.6
epss: 0.00413
license: All rights reserved. Quote with attribution and a link.
---

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

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.4% , percentile 34: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 34% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes org.openidentityplatform.opendj:opendj-server-legacy (Maven) <= 5.1.1, fixed in 5.1.2 . Check your lockfile, including transitive dependencies.

## What it is

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 PROXIEDAUTH 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 PROXIEDAUTH assume any resolvable non-root identity outside the identities permitted by its proxy ACI. The fix returns INVALIDCREDENTIALS (49) before password verification when the target authorization identity is not permitted. This issue is fixed in version 5.1.2.

## Affected packages

- Maven `org.openidentityplatform.opendj:opendj-server-legacy` <= 5.1.1 → fixed: 5.1.2

## Affected products (CVE record)

- OpenIdentityPlatform OpenDJ: < 5.1.2

## Severity

- GitHub_M CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N`
- GitHub CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.41% probability of exploitation activity in the next 30 days; percentile 34.

## Sources

- [GitHub Advisory GHSA-p279-2cqp-84jg](https://github.com/advisories/GHSA-p279-2cqp-84jg)
- [CVE.org record CVE-2026-73644](https://www.cve.org/CVERecord?id=CVE-2026-73644)
- [NVD entry CVE-2026-73644](https://nvd.nist.gov/vuln/detail/CVE-2026-73644)
- [github.com](https://github.com/OpenIdentityPlatform/OpenDJ/security/advisories/GHSA-p279-2cqp-84jg)
- [github.com](https://github.com/OpenIdentityPlatform/OpenDJ/commit/5c326850f1ab945cfca7ac9c5aaf77d1052c6bed)
- [github.com](https://github.com/OpenIdentityPlatform/OpenDJ/releases/tag/5.1.2)

---
Source page: https://erroneo.us/security/cve/CVE-2026-73644/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt