CVE-2017-18892: Github.com/mattermost/mattermost server Mattermost Server Does Not Neutralize Vulnerability
MODERATECVE-2017-18892 is a MODERATE (CVSS 6.1) mattermost server does not neutralize vulnerability (CWE-116: Improper Encoding or Escaping of Output) affecting Github.com/mattermost/mattermost server libraries in the Go ecosystem. The issue involves mattermost server does not neutralize html content in an email template field. Remediation is available by upgrading affected packages to version 4.0.5, 4.1.1, 4.2.0.
CVE-2017-18892 at a Glance
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).
How to Fix CVE-2017-18892
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.
Upgrade github.com/mattermost/mattermost-server to 4.0.5Upgrade github.com/mattermost/mattermost-server to 4.1.1Upgrade github.com/mattermost/mattermost-server to 4.2.0Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/mattermost/mattermost-serverHow to Check if You Are Affected
To determine whether your application is affected by CVE-2017-18892, inspect your project dependencies for Github.com/mattermost/mattermost server:
inspect dependencies for github.com/mattermost/mattermost-serverAnalyze 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 4.0.5), 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-116: Improper Encoding or Escaping of Output, where the product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. as a result, the intended structure of the message is not preserved. 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
CVE-2017-18892 Affected Github.com/mattermost/mattermost server Versions
3 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/mattermost/mattermost-server
|
Go |
< 4.0.5
|
4.0.5
|
|
github.com/mattermost/mattermost-server
|
Go |
≥ 4.1.0
< 4.1.1
|
4.1.1
|
|
github.com/mattermost/mattermost-server
|
Go |
≥ 4.2.0-rc1
< 4.2.0
|
4.2.0
|
References
Frequently Asked Questions
What is CVE-2017-18892?
Which Github.com/mattermost/mattermost server versions are affected?
What version fixes CVE-2017-18892?
Is github.com/mattermost/mattermost-server affected?
What is the CVSS score of CVE-2017-18892?
What CWE is associated with CVE-2017-18892?
How can I check Go dependencies for CVE-2017-18892?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-wj5w-qghh-gvqp",
"modified" : "2026-01-14T21:16:57Z",
"published" : "2022-05-24T17:21:05Z",
"aliases" : [ "CVE-2017-18892" ],
"summary" : "Mattermost Server does not neutralize HTML content in an Email template field",
"details" : "An issue was discovered in Mattermost Server before 4.2.0, 4.1.1, and 4.0.5. E-mail templates can have a field in which HTML content is not neutralized.",
"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" : "4.0.5"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/mattermost/mattermost-server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "4.1.0"
}, {
"fixed" : "4.1.1"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/mattermost/mattermost-server"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "4.2.0-rc1"
}, {
"fixed" : "4.2.0"
} ]
} ]
} ],
"references" : [ {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2017-18892"
}, {
"type" : "WEB",
"url" : "https://github.com/mattermost/mattermost/commit/4e05fbffed4d7ad75c0bb55d67d2c6f7cf9eaad6"
}, {
"type" : "WEB",
"url" : "https://github.com/mattermost/mattermost/commit/d76946bdb545aba4088943fc523dabb459d22873"
}, {
"type" : "WEB",
"url" : "https://github.com/mattermost/mattermost/commit/f5167f3ba645b829f4c28530e13be6c3db967255"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/mattermost/mattermost"
}, {
"type" : "WEB",
"url" : "https://mattermost.com/security-updates"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-116" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2026-01-12T18:25:21Z",
"nvd_published_at" : "2020-06-19T19:15:00Z"
}
}