CVE-2026-22545: Github.com/mattermost/mattermost/server/v8 Mattermost Fails To Validate User's Vulnerability
LOWCVE-2026-22545 is a LOW (CVSS 3.1) mattermost fails to validate user's vulnerability (CWE-863: Incorrect Authorization) affecting Github.com/mattermost/mattermost/server/v8 libraries in the Go ecosystem. The issue involves mattermost fails to validate user's authentication method when processing account auth type switch. Remediation is available by upgrading affected packages to version 8.0.0-20260127144908-ced9a56e3988, 5.3.2-0.20260127144908-ced9a56e3988, 10.11.11, 11.2.3, 11.3.1.
CVE-2026-22545 at a Glance
Security Impact
CVSS: 3.1
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N).
How to Fix CVE-2026-22545
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 8.0.0-20260127144908-ced9a56e3988Upgrade github.com/mattermost/mattermost-server to 5.3.2-0.20260127144908-ced9a56e3988Upgrade github.com/mattermost/mattermost-server to 10.11.11Upgrade github.com/mattermost/mattermost-server to 11.2.3Upgrade github.com/mattermost/mattermost-server to 11.3.1Run 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-2026-22545, 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 8.0.0-20260127144908-ced9a56e3988), 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-2026-22545 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 |
< 8.0.0-20260127144908-ced9a56e3988
|
8.0.0-20260127144908-ced9a56e3988
|
|
github.com/mattermost/mattermost-server
|
Go |
< 5.3.2-0.20260127144908-ced9a56e3988
|
5.3.2-0.20260127144908-ced9a56e3988
|
|
github.com/mattermost/mattermost-server
|
Go |
≥ 10.11.0-rc1
< 10.11.11
|
10.11.11
|
|
github.com/mattermost/mattermost-server
|
Go |
≥ 11.2.0-rc1
< 11.2.3
|
11.2.3
|
|
github.com/mattermost/mattermost-server
|
Go |
≥ 11.3.0-rc1
< 11.3.1
|
11.3.1
|
References
Frequently Asked Questions
What is CVE-2026-22545?
Which Github.com/mattermost/mattermost/server/v8 versions are affected?
What version fixes CVE-2026-22545?
Is github.com/mattermost/mattermost/server/v8 affected?
Is github.com/mattermost/mattermost-server affected?
What is the CVSS score of CVE-2026-22545?
What CWE is associated with CVE-2026-22545?
How can I check Go dependencies for CVE-2026-22545?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-rv67-7w2g-7976",
"modified" : "2026-03-19T19:25:33Z",
"published" : "2026-03-16T15:30:47Z",
"aliases" : [ "CVE-2026-22545" ],
"summary" : "Mattermost fails to validate user's authentication method when processing account auth type switch",
"details" : "Mattermost versions 10.11.x <= 10.11.10 fail to validate user's authentication method when processing account auth type switch which allows an authenticated attacker to change account password without confirmation via falsely claiming a different auth provider.. Mattermost Advisory ID: MMSA-2026-00583",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/mattermost/mattermost/server/v8"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "8.0.0-20260127144908-ced9a56e3988"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/mattermost/mattermost-server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "5.3.2-0.20260127144908-ced9a56e3988"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/mattermost/mattermost-server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "10.11.0-rc1"
}, {
"fixed" : "10.11.11"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/mattermost/mattermost-server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "11.2.0-rc1"
}, {
"fixed" : "11.2.3"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/mattermost/mattermost-server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "11.3.0-rc1"
}, {
"fixed" : "11.3.1"
} ]
} ]
} ],
"references" : [ {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-22545"
}, {
"type" : "WEB",
"url" : "https://github.com/mattermost/mattermost/commit/ced9a56e3988fe9fd4559d45f9971dbd562e2218"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/mattermost/mattermost"
}, {
"type" : "WEB",
"url" : "https://mattermost.com/security-updates"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-863" ],
"severity" : "LOW",
"github_reviewed" : true,
"github_reviewed_at" : "2026-03-19T19:25:33Z",
"nvd_published_at" : "2026-03-16T15:16:21Z"
}
}