{"action":"Upgrade github.com/mattermost/mattermost-server to 10.11.15 or later.","affected":[{"fixed":"11.6.1","introduced":"11.6.0"},{"fixed":"11.5.4","introduced":"11.5.0"},{"fixed":"11.4.5","introduced":"11.4.0"},{"fixed":"10.11.15","introduced":"10.11.0"}],"component":"github.com/mattermost/mattermost-server","cve_ids":["CVE-2026-5755"],"ecosystem":"Go","epss":0.00245,"exploited":false,"fixed_versions":["11.6.1","11.5.4","11.4.5","10.11.15"],"ghsa_id":"GHSA-37j2-3vv8-cf24","id":"tcs_01M5KETDHQRB42GX01EJR7A6KN","modified_at":"2026-07-07T16:11:10.521670559Z","published_at":"2026-05-26T13:30:15Z","references":["https://osv.dev/vulnerability/GHSA-37j2-3vv8-cf24","https://nvd.nist.gov/vuln/detail/CVE-2026-5755","https://github.com/mattermost/mattermost/commit/d37c2d9d50b50963dabd92153adf7ed52016769a","https://github.com/mattermost/mattermost","https://mattermost.com/security-updates"],"severity":{"label":"medium","score":6.5},"sources":[{"source":"osv","source_id":"GHSA-37j2-3vv8-cf24","url":"https://osv.dev/vulnerability/GHSA-37j2-3vv8-cf24"}],"summary":"Mattermost doesn't validate the TIFF IFD offset in the image header before allocating memory"}