CVE-2025-13767: Github.com/mattermost/mattermost/server/v8 Mattermost Doesn't Validate User Channel Vulnerability
MODERATECVE-2025-13767 is a MODERATE (CVSS 4.3) mattermost doesn't validate user channel vulnerability (CWE-863: Incorrect Authorization) affecting Github.com/mattermost/mattermost/server/v8 libraries in the Go ecosystem. The issue involves mattermost doesn't validate user channel membership when attaching mattermost posts as comments to jira issues. Remediation is available by upgrading affected packages to version 8.0.0-20251121122154-b57c297c6d7, 10.11.8, 10.12.4, 11.0.6, 11.1.1.
CVE-2025-13767 at a Glance
Security Impact
CVSS: 4.3
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).
How to Fix CVE-2025-13767
To remediate this vulnerability, upgrade all affected Github.com/mattermost/mattermost/server/v8 dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20251121122154-b57c297c6d7Upgrade github.com/mattermost/mattermost-server to 10.11.8Upgrade github.com/mattermost/mattermost-server to 10.12.4Upgrade github.com/mattermost/mattermost-server to 11.0.6Upgrade github.com/mattermost/mattermost-server to 11.1.1Run 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/v8How to Check if You Are Affected
To determine whether your application is affected by CVE-2025-13767, inspect your project dependencies for Github.com/mattermost/mattermost/server/v8:
inspect dependencies for github.com/mattermost/mattermost/server/v8Analyze the terminal output to locate any version of Github.com/mattermost/mattermost/server/v8 in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 8.0.0-20251121122154-b57c297c6d7), 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-863: Incorrect Authorization, where the product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. In Github.com/mattermost/mattermost/server/v8, 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
CVE-2025-13767 Affected Github.com/mattermost/mattermost/server/v8 Versions
5 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/mattermost/mattermost/server/v8
|
Go |
< 8.0.0-20251121122154-b57c297c6d7
|
8.0.0-20251121122154-b57c297c6d7
|
|
github.com/mattermost/mattermost-server
|
Go |
≥ 10.11.0
< 10.11.8
|
10.11.8
|
|
github.com/mattermost/mattermost-server
|
Go |
≥ 10.12.0
< 10.12.4
|
10.12.4
|
|
github.com/mattermost/mattermost-server
|
Go |
≥ 11.0.0
< 11.0.6
|
11.0.6
|
|
github.com/mattermost/mattermost-server
|
Go |
≥ 11.1.0
< 11.1.1
|
11.1.1
|
References
Frequently Asked Questions
What is CVE-2025-13767?
Which Github.com/mattermost/mattermost/server/v8 versions are affected?
What version fixes CVE-2025-13767?
Is github.com/mattermost/mattermost/server/v8 affected?
Is github.com/mattermost/mattermost-server affected?
What is the CVSS score of CVE-2025-13767?
What CWE is associated with CVE-2025-13767?
How can I check Go dependencies for CVE-2025-13767?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-fmqf-pmcm-8cx9",
"modified" : "2026-02-27T22:04:19Z",
"published" : "2025-12-24T09:30:22Z",
"aliases" : [ "CVE-2025-13767" ],
"summary" : "Mattermost doesn't validate user channel membership when attaching Mattermost posts as comments to Jira issues",
"details" : "Mattermost versions 11.1.x <= 11.1.0, 11.0.x <= 11.0.5, 10.12.x <= 10.12.3, 10.11.x <= 10.11.7 fails to validate user channel membership when attaching Mattermost posts as comments to Jira issues, which allows an authenticated attacker with access to the Jira plugin to read post content and attachments from channels they do not have access to.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/mattermost/mattermost/server/v8"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "8.0.0-20251121122154-b57c297c6d7"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/mattermost/mattermost-server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "10.11.0"
}, {
"fixed" : "10.11.8"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/mattermost/mattermost-server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "10.12.0"
}, {
"fixed" : "10.12.4"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/mattermost/mattermost-server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "11.0.0"
}, {
"fixed" : "11.0.6"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/mattermost/mattermost-server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "11.1.0"
}, {
"fixed" : "11.1.1"
} ]
} ]
} ],
"references" : [ {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-13767"
}, {
"type" : "WEB",
"url" : "https://github.com/mattermost/mattermost/pull/34551"
}, {
"type" : "WEB",
"url" : "https://github.com/mattermost/mattermost/commit/b57c297c6d7ae6812d85e32a625806ac9555deee"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/mattermost/mattermost"
}, {
"type" : "WEB",
"url" : "https://mattermost.com/security-updates"
}, {
"type" : "WEB",
"url" : "https://pkg.go.dev/vuln/GO-2026-4259"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-863" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2025-12-26T18:40:17Z",
"nvd_published_at" : "2025-12-24T08:15:45Z"
}
}