{"id":"CVE-2018-21259","details":"An issue was discovered in Mattermost Server before 4.10.1, 4.9.4, and 4.8.2. It allows attackers to cause a denial of service (application hang) via a malformed link in a channel.","modified":"2026-07-08T16:40:46.785791Z","published":"2020-06-19T17:15:12.850Z","references":[{"type":"ADVISORY","url":"https://mattermost.com/security-updates/"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mattermost/mattermost","events":[{"introduced":"0"},{"fixed":"62255442b3adea3a5a5435b982c95fa674b573cb"},{"introduced":"3176e13b1f9b14192bef2337ff3fb9346f26ef66"},{"fixed":"416c7523c3097af6759b7c40075df51d44624672"},{"introduced":"9301e575c880970dc5642605adcc37903d176227"},{"fixed":"b28fb65a4b53ee7461567e9d04fca58abe4fc054"}],"database_specific":{"cpe":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"4.8.2"},{"introduced":"4.9.0"},{"fixed":"4.9.4"},{"introduced":"4.10.0"},{"fixed":"4.10.1"}],"source":"CPE_RANGE"}}],"versions":["v4.10.0-rc5","v4.10.0-rc4","v4.10.0","v4.9.1-rc1","v4.9.1","v4.9.0-rc6","v4.9.0","v4.8.1-rc1","v4.8.1","v4.8.0-rc6","v4.8.0-rc5","v4.8.0","v4.8.0-rc4","v4.8.0-rc3","v4.8.0-rc2","v4.8.0-rc1","v4.7.0-rc1","v4.6.0-rc2","v4.6.0-rc1","v4.5.0-rc1","v4.4.0-rc1","v4.3.0-rc1","v4.2.0-rc1","v0.5.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2018-21259.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"}]}