{"document":{"category":"csaf_vex","csaf_version":"2.0","title":"CVE-2026-6961: CVE-2026-6961: Path traversal via unsanitized FileInfo.Name in Mattermost federation sync","publisher":{"category":"vendor","name":"HarborGuard Database","namespace":"https://database.harborguard.co"},"tracking":{"id":"CVE-2026-6961","status":"final","version":"1","initial_release_date":"2026-06-12T15:56:17.364Z","current_release_date":"2026-06-16T13:17:18.192Z","revision_history":[{"date":"2026-06-12T15:56:17.364Z","number":"1","summary":"Initial machine-readable export from HarborGuard."}]},"distribution":{"tlp":{"label":"WHITE"},"text":"Public CVE data; freely redistributable."},"notes":[{"category":"description","text":"Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Mattermost fails to sanitize FileInfo.Name received from federated peers during shared channel file sync, which allows an attacker who controls a federated server to write files to arbitrary locations within the target server's filestore via path traversal sequences in the filename field.. Mattermost Advisory ID: MMSA-2026-00661","title":"CVE description"}],"references":[{"category":"self","summary":"CVE-2026-6961 on HarborGuard Database","url":"https://database.harborguard.co/cve/CVE-2026-6961"},{"category":"external","summary":"CVE Record","url":"https://www.cve.org/CVERecord?id=CVE-2026-6961"},{"category":"external","summary":"MMSA-2026-00661","url":"https://mattermost.com/security-updates"}]},"product_tree":{"branches":[{"category":"vendor","name":"Mattermost","branches":[{"category":"product_name","name":"Mattermost","branches":[{"category":"product_version_range","name":">=11.6.0 <=11.6.1","product":{"name":"Mattermost Mattermost >=11.6.0 <=11.6.1","product_id":"CSAFPID-1","product_identification_helper":{"cpe":"cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=11.5.0 <=11.5.4","product":{"name":"Mattermost Mattermost >=11.5.0 <=11.5.4","product_id":"CSAFPID-2","product_identification_helper":{"cpe":"cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=10.11.0 <=10.11.15","product":{"name":"Mattermost Mattermost >=10.11.0 <=10.11.15","product_id":"CSAFPID-3","product_identification_helper":{"cpe":"cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*"}}},{"category":"product_version_range","name":">=10.11.0 <=10.11.16","product":{"name":"Mattermost Mattermost >=10.11.0 <=10.11.16","product_id":"CSAFPID-4","product_identification_helper":{"cpe":"cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"11.7.0","product":{"name":"Mattermost Mattermost 11.7.0","product_id":"CSAFPID-5","product_identification_helper":{"cpe":"cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"11.6.2","product":{"name":"Mattermost Mattermost 11.6.2","product_id":"CSAFPID-6","product_identification_helper":{"cpe":"cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"11.5.5","product":{"name":"Mattermost Mattermost 11.5.5","product_id":"CSAFPID-7","product_identification_helper":{"cpe":"cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"10.11.16","product":{"name":"Mattermost Mattermost 10.11.16","product_id":"CSAFPID-8","product_identification_helper":{"cpe":"cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*"}}},{"category":"product_version","name":"10.11.17","product":{"name":"Mattermost Mattermost 10.11.17","product_id":"CSAFPID-9","product_identification_helper":{"cpe":"cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*"}}}]}]}]},"vulnerabilities":[{"cve":"CVE-2026-6961","title":"CVE-2026-6961: Path traversal via unsanitized FileInfo.Name in Mattermost federation sync","notes":[{"category":"description","text":"Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Mattermost fails to sanitize FileInfo.Name received from federated peers during shared channel file sync, which allows an attacker who controls a federated server to write files to arbitrary locations within the target server's filestore via path traversal sequences in the filename field.. Mattermost Advisory ID: MMSA-2026-00661","title":"CVE description"}],"product_status":{"known_affected":["CSAFPID-1","CSAFPID-2","CSAFPID-3","CSAFPID-4"],"fixed":["CSAFPID-5","CSAFPID-6","CSAFPID-7","CSAFPID-8","CSAFPID-9"]},"scores":[{"cvss_v3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:L","baseScore":7.6,"baseSeverity":"HIGH"},"products":["CSAFPID-1","CSAFPID-2","CSAFPID-3","CSAFPID-4"]}],"remediations":[{"category":"vendor_fix","details":"Update to a fixed version: 10.11.16, 10.11.17, 11.5.5, 11.6.2, 11.7.0.","product_ids":["CSAFPID-1","CSAFPID-2","CSAFPID-3","CSAFPID-4"]}]}]}