# CVE-2026-49939: Apache James: Negative IMAP ACL administer authorization bypass through JMAP protocol

Status: published. Published: 2026-11-06. Updated: 2026-11-06.

In Apache James server prior version 3.9.1 improper Access Control List processing is exposed by the JMAP protocol which do not account for negative rules positionned by IMAP protocol.

This results in users being able to administer folders in JMAP despite having being explicitly denied the right to do so in IMAP.

Users are recommended to upgrade to version 3.9.1 which fixes this issue.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- Apache Software Foundation / Apache James: ≥ 3.9.0; < 3.9.1 (affected, semver). Source: CNA: apache

## Severity and prioritization

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-284

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://lists.apache.org/thread.html/7qwsmkk88xbfq4q9o0pz9bt8p9p1yjs7 (CNA: apache; vendor-advisory)

## Provenance

- CNA: apache: https://www.cve.org/CVERecord?id=CVE-2026-49939; retrieved 2026-11-06; source updated 2026-11-06

Revision: bf355fbea014fdfa21c5fd5dd394826e9925e258ada81703a81793f993d09ab2

Canonical: https://y2.dev/cve/CVE-2026-49939

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