CVE-2026-49939: Apache James JMAP ACL bypass
JMAP protocol fails to respect negative IMAP ACL rules, letting users administer folders despite denials; upgrade to 3.9.1 required.
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CVE-2026-49939
JMAP ACL bypass in Apache James before 3.9.1
- CVSS 3.1
- 7.5 high
- EPSS
- —
- Published
- ·
- Modified
AI analysisSummaries by Vani AI
Apache James server prior to 3.9.1 has improper ACL processing exposed via JMAP that ignores negative rules from IMAP. Users can administer folders through JMAP despite IMAP denial. An attacker gains folder control on James servers via JMAP. Apache James server users are affected.
What to do: Upgrade to Apache James 3.9.1.
| Product | Affected | Fixed in |
|---|---|---|
| Apache James | < 3.9.1 | 3.9.1 |
Estimated exposure
No basis for an estimate.
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Description · NVD
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.
- Weakness
- CWE-284
- Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N