{"cve":"CVE-2026-28736","nvd":{"published":"2026-04-03T14:16:29.517","modified":"2026-10-23T22:10:00.160","status":"Analyzed","description":"** UNSUPPORTED WHEN ASSIGNED ** Focalboard version 8.0 fails to validate file ownership when serving uploaded files. This allows an authenticated attacker who knows a victim's fileID to read the content of the file. NOTE: Focalboard as a standalone product is not maintained and no fix will be issued.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","score":4.3},"cwes":["CWE-639"],"references":["https://github.com/mattermost-community/focalboard"],"products":["mattermost:focalboard"],"source":"nvd","synced_at":"2026-10-24T16:53:27.712498749+00:00"},"epss":{"cve":"CVE-2026-28736","score":0.00221,"percentile":0.12555,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-vph7-r229-qxpf","url":"https://osv.dev/vulnerability/GHSA-vph7-r229-qxpf","summary":"Focalboard doesn't validate file ownership when serving uploaded files","modified":"2026-06-25T23:11:35.902827145Z","packages":[{"ecosystem":"Go","name":"github.com/mattermost/focalboard","purl":"pkg:golang/github.com/mattermost/focalboard","ranges":["<=7.10.6"],"fixed":[]}]},{"id":"GO-2026-5670","url":"https://osv.dev/vulnerability/GO-2026-5670","summary":"Focalboard doesn't validate file ownership when serving uploaded files in github.com/mattermost/focalboard","modified":"2026-06-25T23:01:38.778614136Z","packages":[{"ecosystem":"Go","name":"github.com/mattermost/focalboard","purl":"pkg:golang/github.com/mattermost/focalboard","ranges":["all versions"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}