{"action":"Upgrade github.com/mattermost/mattermost-server to 3.10.2+incompatible or later.","affected":[{"fixed":"3.10.2+incompatible","introduced":"3.10.0+incompatible"}],"component":"github.com/mattermost/mattermost-server","cve_ids":["CVE-2017-18907"],"ecosystem":"Go","epss":0.0069,"exploited":false,"fixed_versions":["3.10.2+incompatible"],"ghsa_id":"GHSA-42x9-rr3c-gr59","id":"tcs_01M5KGDVN5DFQ9W55X81YKER91","modified_at":"2026-02-19T20:41:02.522703Z","published_at":"2026-02-17T18:09:06Z","references":["https://osv.dev/vulnerability/GO-2026-4459","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"],"severity":{"label":"unknown"},"sources":[{"source":"osv","source_id":"GO-2026-4459","url":"https://osv.dev/vulnerability/GO-2026-4459"}],"summary":"Mattermost Server vulnerable to XSS through channel headers in github.com/mattermost/mattermost-server"}