CVE-2026-3113: Github.com/mattermost/mattermost server Mattermost Doesn't Set Permissions On Vulnerability

MODERATE
Advisory Identifier: GHSA-4765-v66x-rqx7
CVSS 5.0
CWE-732
Published
Advisory Summary

CVE-2026-3113 is a MODERATE (CVSS 5.0) mattermost doesn't set permissions on vulnerability (CWE-732: Incorrect Permission Assignment for Critical Resource) affecting Github.com/mattermost/mattermost server libraries in the Go ecosystem. The issue involves mattermost doesn't set permissions on downloaded bulk export. Remediation is available by upgrading affected packages to version 11.4.1, 11.3.2, 11.2.4, 10.11.12, 8.0.0-20260217110922-b7d4a1f1f59b.

CVE-2026-3113 at a Glance

CVE Identifier CVE-2026-3113
GHSA Identifier GHSA-4765-v66x-rqx7
Severity MODERATE
CVSS v3.1 Base Score 5.0
CWE Classification CWE-732: Incorrect Permission Assignment for Critical Resource
Affected Product Github.com/mattermost/mattermost server
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 5.0

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

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-3113

To remediate this vulnerability, upgrade all affected Github.com/mattermost/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: 11.4.1
Upgrade github.com/mattermost/mattermost-server to 11.4.1
github.com/mattermost/mattermost-server fixed: 11.3.2
Upgrade github.com/mattermost/mattermost-server to 11.3.2
github.com/mattermost/mattermost-server fixed: 11.2.4
Upgrade github.com/mattermost/mattermost-server to 11.2.4
github.com/mattermost/mattermost-server fixed: 10.11.12
Upgrade github.com/mattermost/mattermost-server to 10.11.12
github.com/mattermost/mattermost-server fixed: 8.0.0-20260217110922-b7d4a1f1f59b
Upgrade github.com/mattermost/mattermost-server to 8.0.0-20260217110922-b7d4a1f1f59b
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-2026-3113, inspect your project dependencies for Github.com/mattermost/mattermost server:

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

Analyze the terminal output to locate any version of Github.com/mattermost/mattermost server in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 11.4.1), 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-732: Incorrect Permission Assignment for Critical Resource, where the product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors. In Github.com/mattermost/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

Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to set permissions on downloaded bulk export which allows other local users on the server to be able to read contents of the bulk export. Mattermost Advisory ID: MMSA-2026-00593.

CVE-2026-3113 Affected Github.com/mattermost/mattermost server Versions

5 component(s)
Fixed Versions:
11.4.111.3.211.2.410.11.128.0.0-20260217110922-b7d4a1f1f59b
Product / Package Ecosystem Affected Versions Fixed Version
github.com/mattermost/mattermost-server
Go
≥ 11.4.0-rc1
< 11.4.1
11.4.1
github.com/mattermost/mattermost-server
Go
≥ 11.3.0-rc1
< 11.3.2
11.3.2
github.com/mattermost/mattermost-server
Go
≥ 11.2.0-rc1
< 11.2.4
11.2.4
github.com/mattermost/mattermost-server
Go
≥ 10.11.0-rc1
< 10.11.12
10.11.12
github.com/mattermost/mattermost-server
Go
≥ 8.0.0-20260105080200-d27a2195068d
< 8.0.0-20260217110922-b7d4a1f1f59b
8.0.0-20260217110922-b7d4a1f1f59b

References

Frequently Asked Questions

What is CVE-2026-3113?
CVE-2026-3113 is a security vulnerability in Github.com/mattermost/mattermost server involving Mattermost doesn't set permissions on downloaded bulk export under CWE-732: Incorrect Permission Assignment for Critical Resource.
Which Github.com/mattermost/mattermost server versions are affected?
Affected versions include releases prior to 11.4.1, 11.3.2, 11.2.4, 10.11.12, 8.0.0-20260217110922-b7d4a1f1f59b across affected packages: github.com/mattermost/mattermost-server.
What version fixes CVE-2026-3113?
Upgrading to 11.4.1, 11.3.2, 11.2.4, 10.11.12, 8.0.0-20260217110922-b7d4a1f1f59b (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 11.4.1, 11.3.2, 11.2.4, 10.11.12, 8.0.0-20260217110922-b7d4a1f1f59b. Upgrade your dependency to 11.4.1, 11.3.2, 11.2.4, 10.11.12, 8.0.0-20260217110922-b7d4a1f1f59b or later.
What is the CVSS score of CVE-2026-3113?
CVE-2026-3113 has a CVSS v3.1 base score of 5.0 (MODERATE) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2026-3113?
CVE-2026-3113 is classified under CWE-732: Incorrect Permission Assignment for Critical Resource (The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.).
How can I check Go dependencies for CVE-2026-3113?
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
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-4765-v66x-rqx7",
  "modified" : "2026-03-31T23:04:51Z",
  "published" : "2026-03-26T18:31:42Z",
  "aliases" : [ "CVE-2026-3113" ],
  "summary" : "Mattermost doesn't set permissions on downloaded bulk export",
  "details" : "Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to set permissions on downloaded bulk export which allows other local users on the server to be able to read contents of the bulk export. Mattermost Advisory ID: MMSA-2026-00593.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.4.0-rc1"
      }, {
        "fixed" : "11.4.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.3.0-rc1"
      }, {
        "fixed" : "11.3.2"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.2.0-rc1"
      }, {
        "fixed" : "11.2.4"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.11.0-rc1"
      }, {
        "fixed" : "10.11.12"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/mattermost/mattermost-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0-20260105080200-d27a2195068d"
      }, {
        "fixed" : "8.0.0-20260217110922-b7d4a1f1f59b"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-3113"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/mattermost/mattermost"
  }, {
    "type" : "WEB",
    "url" : "https://mattermost.com/security-updates"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-732" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-31T23:04:51Z",
    "nvd_published_at" : "2026-03-26T17:16:42Z"
  }
}