OpenDJ SASL PLAIN authzid bypassing the proxy ACI scope check

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.6 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

EPSS

• CVE-2026-73644: 0.41% estimated exploitation activity in the next 30 days; percentile 35.57 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary When a SASL PLAIN bind supplies an authorization identity (authzid) that resolves to a different user, PlainSASLMechanismHandler verified only the PROXIEDAUTH privilege and never evaluated the "proxy" access-control right (the mayProxy ACI scope check). As a result, any account holding the proxied-auth privilege could assume any resolvable non-root identity without being granted a proxy ACI for that target. This diverges from every other proxy path in OpenDJ — the proxied-authorization controls (RFC 4370) and the DIGEST-MD5 / GSSAPI authzid handlers all require both the privilege and the mayProxy scope grant. Impact Privilege escalation / authorization bypass: a holder of proxied-auth can act as arbitrary directory users beyond the scope intended by the deployment's proxy ACIs, defeating the ACI-based restriction on which identities may be impersonated. Root/Directory Manager is not assumable this way. Fix Enforce the mayProxy scope check on the SASL PLAIN authzid path (both…

Published by the source

24 Jul 2026, 21:46 UTC

Last modified by the source

13 Aug 2026, 17:52 UTC

Source last checked

26 Oct 2026, 16:54 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-p279-2cqp-84jg

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# Patch Next advisory brief: CVE-2026-73644

Advisory: OpenDJ SASL PLAIN authzid bypassing the proxy ACI scope check
IDs: CVE-2026-73644, GHSA-p279-2cqp-84jg
Record: https://patchnext.com/advisories/cve-2026-73644 (revision 1, source checked 26 Oct 2026, 16:54 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.6)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.openidentityplatform.opendj:opendj-server-legacy 5.1.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.openidentityplatform.opendj:opendj-server-legacy: affected <= 5.1.1; fixed in 5.1.2

## Suggested inspection (read-only)
- Maven org.openidentityplatform.opendj:opendj-server-legacy: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.openidentityplatform.opendj:opendj-server-legacy.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-p279-2cqp-84jg (GitHub-reviewed advisory GHSA-p279-2cqp-84jg lists affected ranges: Maven org.openidentityplatform.opendj:opendj-server-legacy >=0 <=5.1.1)

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