GO-2026-4459

    Dashboard / Vulnerabilities / GO-2026-4459

    GO-2026-4459

    Published: 17 Feb 2026Last Modified: 19 Feb 2026

    Summary: Mattermost Server vulnerable to XSS through channel headers in github.com/mattermost/mattermost-server

    Details: Mattermost Server vulnerable to XSS through channel headers in github.com/mattermost/mattermost-server. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. (If this is causing false-positive reports from vulnerability scanners, please suggest an edit to the report.) The additional affected modules and versions are: github.com/mattermost/mattermost-server before v3.9.2-0.20170714014920-312269ad0bd1.

    References: https://github.com/advisories/GHSA-42x9-rr3c-gr59, https://nvd.nist.gov/vuln/detail/CVE-2017-18907, https://github.com/mattermost/mattermost/commit/312269ad0bd166174f07f9df7391fce714601600, https://github.com/mattermost/mattermost/commit/4519b03d95e8bfe1b2f74094673ae1a2f39f6b47, https://github.com/mattermost/mattermost/commit/a18479df0940be8503c9b88993490741793eba9e, https://mattermost.com/security-updates

    Affected packages

    Package

    Name: github.com/mattermost/mattermost-server

    Purl: pkg:golang/github.com/mattermost/mattermost-server

    Affected ranges

    Type: SEMVER

    Events:

    Introduced- 3.10.0+incompatible
    Fixed -3.10.2+incompatible

    Affected versions

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    GO-2026-4459 | CVE-DB