1. Home
  2. Vulnerabilities
  3. CVE-2026-49939
0.0
NA
CVE-2026-49939
Apache James: Negative IMAP ACL administer authorization bypass through JMAP protocol
Overview
Description

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.

Details
INFO

Published Date :

Nov. 6, 2026, 12:17 p.m.

Last Modified :

Nov. 6, 2026, 12:17 p.m.

Remotely Exploit :

No

Source :

[email protected]
Impact
Affected Products

The following products are affected by CVE-2026-49939 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Apache james
: Total Affected Vendor : 1 | Products : 1
Solution
Upgrade Apache James server to version 3.9.1 or later to fix improper Access Control List processing.
  • Upgrade Apache James server to version 3.9.1 or later.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-49939.

URL Resource
https://lists.apache.org/thread.html/7qwsmkk88xbfq4q9o0pz9bt8p9p1yjs7
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-49939 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-49939 weaknesses.

CAPEC-19: Embedding Scripts within Scripts Embedding Scripts within Scripts CAPEC-441: Malicious Logic Insertion Malicious Logic Insertion CAPEC-478: Modification of Windows Service Configuration Modification of Windows Service Configuration CAPEC-479: Malicious Root Certificate Malicious Root Certificate CAPEC-502: Intent Spoof Intent Spoof CAPEC-503: WebView Exposure WebView Exposure CAPEC-536: Data Injected During Configuration Data Injected During Configuration CAPEC-546: Incomplete Data Deletion in a Multi-Tenant Environment Incomplete Data Deletion in a Multi-Tenant Environment CAPEC-550: Install New Service Install New Service CAPEC-551: Modify Existing Service Modify Existing Service CAPEC-552: Install Rootkit Install Rootkit CAPEC-556: Replace File Extension Handlers Replace File Extension Handlers CAPEC-558: Replace Trusted Executable Replace Trusted Executable CAPEC-562: Modify Shared File Modify Shared File CAPEC-563: Add Malicious File to Shared Webroot Add Malicious File to Shared Webroot CAPEC-564: Run Software at Logon Run Software at Logon CAPEC-578: Disable Security Software Disable Security Software

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-49939 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-49939 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Nov. 06, 2026

    Action Type Old Value New Value
    Added Description 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.
    Added CWE CWE-284
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/49xxx/CVE-2026-49939.json">CVE-2026-49939</a>
    Added Reference https://lists.apache.org/thread.html/7qwsmkk88xbfq4q9o0pz9bt8p9p1yjs7
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
No CVSS metrics available for this vulnerability.