{"action":"Upgrade github.com/syncthing/syncthing to 1.15.0 or later.","affected":[{"fixed":"1.15.0","introduced":"0"}],"component":"github.com/syncthing/syncthing","cve_ids":["CVE-2021-21404"],"ecosystem":"Go","epss":0.0197,"exploited":false,"fixed_versions":["1.15.0"],"ghsa_id":"GHSA-x462-89pf-6r5h","id":"tcs_01M5KFRH6H943FX11WHXEX36W3","modified_at":"2026-07-08T06:30:05.046463672Z","published_at":"2021-05-21T16:23:17Z","references":["https://osv.dev/vulnerability/GHSA-x462-89pf-6r5h","https://github.com/syncthing/syncthing/security/advisories/GHSA-x462-89pf-6r5h","https://nvd.nist.gov/vuln/detail/CVE-2021-21404","https://github.com/syncthing/syncthing/commit/fb4fdaf4c0a79c22cad000c42ac1394e3ccb6a97","https://github.com/syncthing/syncthing/releases/tag/v1.15.0","https://pkg.go.dev/github.com/syncthing/syncthing"],"severity":{"label":"high","score":7.5},"sources":[{"source":"osv","source_id":"GHSA-x462-89pf-6r5h","url":"https://osv.dev/vulnerability/GHSA-x462-89pf-6r5h"}],"summary":"Crash due to malformed relay protocol message"}