{"action":"Upgrade github.com/mattermost/mattermost-server to 4.1.2+incompatible or later.","affected":[{"fixed":"4.1.2+incompatible","introduced":"0"},{"fixed":"4.2.1+incompatible","introduced":"4.2.0+incompatible"},{"fixed":"4.3.0+incompatible","introduced":"4.3.0-rc1+incompatible"}],"component":"github.com/mattermost/mattermost-server","cve_ids":["CVE-2017-18879"],"ecosystem":"Go","epss":0.0069,"exploited":false,"fixed_versions":["4.1.2+incompatible","4.2.1+incompatible","4.3.0+incompatible"],"ghsa_id":"GHSA-498j-wxww-j897","id":"tcs_01M5KGC62GDAM2GKX3QD02KC67","modified_at":"2026-03-03T04:57:45.002321Z","published_at":"2025-12-08T21:31:36Z","references":["https://osv.dev/vulnerability/GO-2025-4189","https://github.com/advisories/GHSA-498j-wxww-j897","https://nvd.nist.gov/vuln/detail/CVE-2017-18879","https://mattermost.com/security-updates"],"severity":{"label":"unknown"},"sources":[{"source":"osv","source_id":"GO-2025-4189","url":"https://osv.dev/vulnerability/GO-2025-4189"}],"summary":"Mattermost Server is vulnerable to XSS through author_link field in Slack attachments in github.com/mattermost/mattermost-server"}