{"cve":"CVE-2026-3637","nvd":{"published":"2026-05-18T08:16:14.040","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 check the create_post channel permission during post edit operations which allows an authenticated attacker with revoked posting privileges to modify their existing posts via direct API requests to the post update and patch endpoints.. Mattermost Advisory ID: MMSA-2026-00627","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-862"],"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-2026-3637","score":0.00152,"percentile":0.04301,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-v549-xx3c-6pc8","url":"https://osv.dev/vulnerability/GHSA-v549-xx3c-6pc8","summary":"Mattermost doesn't check the create_post channel permission during post edit operations","modified":"2026-06-25T23:11:38.862474425Z","packages":[{"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":["<8.0.0-20260316171743-090408f09f53"],"fixed":["8.0.0-20260316171743-090408f09f53"]},{"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","purl":"pkg:golang/github.com/mattermost/mattermost-server","ranges":["<5.3.2-0.20260316171743-090408f09f53"],"fixed":["5.3.2-0.20260316171743-090408f09f53"]}]},{"id":"GO-2026-5651","url":"https://osv.dev/vulnerability/GO-2026-5651","summary":"Mattermost doesn't check the create_post channel permission during post edit operations in github.com/mattermost/mattermost-server","modified":"2026-06-25T23:01:37.454131782Z","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":["<8.0.0-20260316171743-090408f09f53"],"fixed":["8.0.0-20260316171743-090408f09f53"]}]}],"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."]}