{"cve":"CVE-2023-40703","nvd":{"published":"2023-11-27T10:15:07.460","modified":"2026-06-17T06:19:08.777","status":"Modified","description":"Mattermost fails to properly limit the characters allowed in different fields of a block in Mattermost Boards allowing a attacker to consume excessive resources, possibly leading to Denial of Service, by patching the field of a block using a specially crafted string.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-400"],"references":["https://mattermost.com/security-updates","https://mattermost.com/security-updates"],"products":["mattermost:mattermost"],"source":"nvd","synced_at":"2026-10-19T21:42:07.670898610+00:00"},"epss":{"cve":"CVE-2023-40703","score":0.00723,"percentile":0.54036,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-c37r-v8jx-7cv2","url":"https://osv.dev/vulnerability/GHSA-c37r-v8jx-7cv2","summary":"Mattermost Uncontrolled Resource Consumption vulnerability","modified":"2026-09-10T03:49:58.926738876Z","packages":[{"ecosystem":"Go","name":"github.com/mattermost/mattermost/server/v8","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8","ranges":[">=9.1.0 <9.1.1"],"fixed":["9.1.1"]},{"ecosystem":"Go","name":"github.com/mattermost/mattermost/server/v8","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8","ranges":[">=9.0.0 <9.0.2"],"fixed":["9.0.2"]},{"ecosystem":"Go","name":"github.com/mattermost/mattermost/server/v8","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8","ranges":["<8.1.4"],"fixed":["8.1.4"]},{"ecosystem":"Go","name":"github.com/mattermost/mattermost-server/v6","purl":"pkg:golang/github.com/mattermost/mattermost-server/v6","ranges":["<7.8.13"],"fixed":["7.8.13"]}]}],"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."]}