CVE-2026-103659: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-r4v7-fgm4-552c
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CWE-285
Published
Advisory Summary

CVE-2026-103659 is a HIGH security vulnerability vulnerability (CWE-285: Improper Authorization) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-103659 at a Glance

CVE Identifier CVE-2026-103659
GHSA Identifier GHSA-r4v7-fgm4-552c
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-285: Improper Authorization
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-103659

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-103659, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-285: Improper Authorization, where the product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

MISP contains an authorization bypass in the event flattening feature. When a user requests an event with the flatten option enabled, the application removes the Object containment from the query and returns object attributes as top-level event attributes. In doing so, the object-level distribution and sharing-group access control check was not re-applied to those attributes. As a result, a user who can view a community-distributed event could retrieve attributes belonging to organisation-only objects (distribution level 0) or objects restricted to a specific sharing group, even though the user's organisation does not have access to those objects. This constitutes an unauthorized disclosure of sensitive threat intelligence data. A secondary issue was introduced by the initial remediation: the fix reused the full Object contain conditions (including soft-delete state) as the gate for flattened attributes, causing an event owner requesting deleted attributes to lose all attributes whose parent object was still live. The final fix isolates the distribution ACL condition as the sole gate. Preconditions: - An authenticated user with access to a community-distributed event - The event contains at least one object with a distribution level or sharing group that restricts access beyond the event's own distribution Impact: - Unauthorized disclosure of attributes belonging to restricted objects - Potential exposure of organisation-specific threat intelligence to other organisations Affected versions: <2.5.48

References

NVD — CVE-2026-103659 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-103659
Security Fix Commit FIX COMMIT
https://github.com/MISP/MISP/commit/07f3486d5
Security Fix Commit FIX COMMIT
https://github.com/MISP/MISP/commit/ab08edf92

Frequently Asked Questions

What is CVE-2026-103659?
CVE-2026-103659 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-285: Improper Authorization.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-103659?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-103659?
CVE-2026-103659 is classified under CWE-285: Improper Authorization (The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.).
How can I check Maven dependencies for CVE-2026-103659?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-r4v7-fgm4-552c",
  "modified" : "2026-10-01T09:30:35Z",
  "published" : "2026-10-01T09:30:35Z",
  "aliases" : [ "CVE-2026-103659" ],
  "details" : "MISP contains an authorization bypass in the event flattening feature. When a user requests an event with the flatten option enabled, the application removes the Object containment from the query and returns object attributes as top-level event attributes. In doing so, the object-level distribution and sharing-group access control check was not re-applied to those attributes.\n\nAs a result, a user who can view a community-distributed event could retrieve attributes belonging to organisation-only objects (distribution level 0) or objects restricted to a specific sharing group, even though the user's organisation does not have access to those objects. This constitutes an unauthorized disclosure of sensitive threat intelligence data.\n\nA secondary issue was introduced by the initial remediation: the fix reused the full Object contain conditions (including soft-delete state) as the gate for flattened attributes, causing an event owner requesting deleted attributes to lose all attributes whose parent object was still live. The final fix isolates the distribution ACL condition as the sole gate.\n\nPreconditions:\n\n- An authenticated user with access to a community-distributed event\n\n- The event contains at least one object with a distribution level or sharing group that restricts access beyond the event's own distribution\n\nImpact:\n\n- Unauthorized disclosure of attributes belonging to restricted objects\n\n- Potential exposure of organisation-specific threat intelligence to other organisations\n\nAffected versions: <2.5.48",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-103659"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/MISP/MISP/commit/07f3486d5"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/MISP/MISP/commit/ab08edf92"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-285" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-10-01T09:17:08Z"
  }
}