{"cve":"CVE-2026-4273","nvd":{"published":"2026-05-18T08:16:14.180","modified":"2026-10-14T20:10:00.190","status":"Analyzed","description":"Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation which allows an authenticated attacker to bypass token rotation and reuse the original invite token via sending a crafted invite confirmation with a RefreshedToken matching the original token. Mattermost Advisory ID: MMSA-2026-00575","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-2026-4273","score":0.00142,"percentile":0.03473,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-hqpj-f3jh-29vx","url":"https://osv.dev/vulnerability/GHSA-hqpj-f3jh-29vx","summary":"Mattermost doesn't validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation","modified":"2026-06-25T23:11:31.446397134Z","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":["<8.0.0-20260313190740-742e0be95074"],"fixed":["8.0.0-20260313190740-742e0be95074"]},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server","purl":"pkg:golang/github.com/mattermost/mattermost-server","ranges":["<5.3.2-0.20260313190740-742e0be95074"],"fixed":["5.3.2-0.20260313190740-742e0be95074"]}]},{"id":"GO-2026-5432","url":"https://osv.dev/vulnerability/GO-2026-5432","summary":"Mattermost doesn't validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation in github.com/mattermost/mattermost-server","modified":"2026-06-25T23:01:13.302965013Z","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",">=11.5.0+incompatible <11.5.2+incompatible"],"fixed":["10.11.14+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":["<8.0.0-20260313190740-742e0be95074"],"fixed":["8.0.0-20260313190740-742e0be95074"]}]}],"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."]}