{"cve":"CVE-2026-28732","nvd":{"published":"2026-05-18T09:16:22.570","modified":"2026-10-14T20:10:00.190","status":"Analyzed","description":"Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 Fail to enforce slash command trigger-word uniqueness during command updates which allows an authenticated team member with Manage Own Slash Commands permission to hijack and impersonate existing system or custom slash commands via editing their own slash command trigger to an already-registered trigger through the command update API. Mattermost Advisory ID: MMSA-2026-00597","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","score":4.3},"cwes":["CWE-863"],"references":["https://mattermost.com/security-updates"],"products":["mattermost:mattermost_server"],"source":"nvd","synced_at":"2026-10-19T22:35:16.954578616+00:00"},"epss":{"cve":"CVE-2026-28732","score":0.00152,"percentile":0.04323,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-wvcv-9xpm-7mqc","url":"https://osv.dev/vulnerability/GHSA-wvcv-9xpm-7mqc","summary":"Mattermost doesn't enforce slash command trigger-word uniqueness during command updates","modified":"2026-06-25T23:11:29.688799641Z","packages":[{"ecosystem":"Go","name":"github.com/mattermost/mattermost/server/v8","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8","ranges":[">=11.5.0 <11.5.2"],"fixed":["11.5.2"]},{"ecosystem":"Go","name":"github.com/mattermost/mattermost/server/v8","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8","ranges":[">=10.11.0 <10.11.14"],"fixed":["10.11.14"]},{"ecosystem":"Go","name":"github.com/mattermost/mattermost/server/v8","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8","ranges":[">=11.4.0 <11.4.4"],"fixed":["11.4.4"]},{"ecosystem":"Go","name":"github.com/mattermost/mattermost/server/v8","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8","ranges":["<8.0.0-20260306123948-f5fe8ded6b63"],"fixed":["8.0.0-20260306123948-f5fe8ded6b63"]},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","ranges":["<5.3.2-0.20260306123948-f5fe8ded6b63"],"fixed":["5.3.2-0.20260306123948-f5fe8ded6b63"]}]},{"id":"GO-2026-5726","url":"https://osv.dev/vulnerability/GO-2026-5726","summary":"Mattermost doesn't enforce slash command trigger-word uniqueness during command updates in github.com/mattermost/mattermost-server","modified":"2026-06-25T23:01:40.053823954Z","packages":[{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","ranges":[">=10.11.0+incompatible <10.11.14+incompatible",">=11.4.0+incompatible <11.4.4+incompatible",">=11.5.0+incompatible <11.5.2+incompatible"],"fixed":["10.11.14+incompatible","11.4.4+incompatible","11.5.2+incompatible"]},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server/v5","purl":"pkg:golang/github.com/mattermost/mattermost-server/v5","ranges":["all versions"],"fixed":[]},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server/v6","purl":"pkg:golang/github.com/mattermost/mattermost-server/v6","ranges":["all versions"],"fixed":[]},{"ecosystem":"Go","name":"github.com/mattermost/mattermost/server/v8","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8","ranges":["<8.0.0-20260306123948-f5fe8ded6b63"],"fixed":["8.0.0-20260306123948-f5fe8ded6b63"]}]}],"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."]}