CVE-2016-11083: Mattermost Server Files May Be Rendered Inline Vulnerability

MODERATE
Advisory Identifier: GHSA-rm24-25xm-9454
Share
CVSS 6.1
CWE-79
Published
Advisory Summary

CVE-2016-11083 is a MODERATE (CVSS 6.1) files may be rendered inline vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Mattermost Server libraries in the Go ecosystem. The issue involves files may be rendered inline instead of downloaded, allowing script execution. Remediation is available by upgrading affected packages to version 2.2.0.

CVE-2016-11083 at a Glance

CVE Identifier CVE-2016-11083
GHSA Identifier GHSA-rm24-25xm-9454
Severity MODERATE
CVSS v3.1 Base Score 6.1
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Mattermost Server
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 6.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Changed (S:C)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2016-11083

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

github.com/mattermost/mattermost-server fixed: 2.2.0 
Upgrade github.com/mattermost/mattermost-server to 2.2.0
Verify Direct and Transitive Dependencies

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

inspect dependencies for github.com/mattermost/mattermost-server

How to Check if You Are Affected

To determine whether your application is affected by CVE-2016-11083, inspect your project dependencies for Mattermost Server:

inspect dependencies for github.com/mattermost/mattermost-server

Analyze the terminal output to locate any version of Mattermost Server in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.2.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Mattermost Server, 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

An issue was discovered in Mattermost Server before 2.2.0. It allows XSS because it configures files to be opened in a browser window.

CVE-2016-11083 Affected Mattermost Server Versions

1 component(s)
Fixed Versions:
2.2.0
Product / Package Ecosystem Affected Versions Fixed Version
github.com/mattermost/mattermost-server
golang/github.com/mattermost/mattermost-server
Go
< 2.2.0
2.2.0

References

NVD — CVE-2016-11083 NVD
https://nvd.nist.gov/vuln/detail/CVE-2016-11083
Security Fix Commit FIX COMMIT
https://github.com/mattermost/mattermost/commit/480308b7029a04cf41d0e9e7cd68b52dc2138e98
Mattermost Server Source Repository REPOSITORY
https://github.com/mattermost/mattermost
Mattermost Server Security Information SECURITY
https://mattermost.com/security-updates

Frequently Asked Questions

What is CVE-2016-11083?
CVE-2016-11083 is a security vulnerability in Mattermost Server involving Files may be rendered inline instead of downloaded, allowing script execution under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Mattermost Server versions are affected?
Affected versions include releases prior to 2.2.0 across affected packages: github.com/mattermost/mattermost-server.
What version fixes CVE-2016-11083?
Upgrading to 2.2.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/mattermost/mattermost-server affected?
Yes, github.com/mattermost/mattermost-server is affected in releases prior to 2.2.0. Upgrade your dependency to 2.2.0 or later.
What is the CVSS score of CVE-2016-11083?
CVE-2016-11083 has a CVSS v3.1 base score of 6.1 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2016-11083?
CVE-2016-11083 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check Go dependencies for CVE-2016-11083?
Run the dependency tree command: 'inspect dependencies for github.com/mattermost/mattermost-server'. 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-rm24-25xm-9454",
  "modified" : "2025-10-22T21:58:04Z",
  "published" : "2022-05-24T17:21:02Z",
  "aliases" : [ "CVE-2016-11083" ],
  "summary" : "Mattermost Server: Files may be rendered inline instead of downloaded, allowing script execution",
  "details" : "An issue was discovered in Mattermost Server before 2.2.0. It allows XSS because it configures files to be opened in a browser window.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.2.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2016-11083"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mattermost/mattermost/commit/480308b7029a04cf41d0e9e7cd68b52dc2138e98"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/mattermost/mattermost"
  }, {
    "type" : "WEB",
    "url" : "https://mattermost.com/security-updates"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-10-22T21:58:04Z",
    "nvd_published_at" : "2020-06-19T20:15:00Z"
  }
}