{"id":"EUVD-2026-30755","enisaUuid":"9ee05342-12d8-3aa9-a957-706cc9d10dbf","description":"Mattermost versions 11.5.x \u003c\u003d 11.5.1, 10.11.x \u003c\u003d 10.11.13 fail to validate the Host header when constructing response URLs for custom slash commands which allows an authenticated attacker to redirect slash command responses to an attacker-controlled server via a spoofed Host header.. Mattermost Advisory ID: MMSA-2026-00582","datePublished":"May 18, 2026, 8:41:29 AM","dateUpdated":"May 19, 2026, 5:19:42 PM","baseScore":3.5,"baseScoreVersion":"3.1","baseScoreVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N","references":"https://mattermost.com/security-updates\n","aliases":"CVE-2026-6333\nGHSA-vqp5-2mrp-qqxg\n","assigner":"Mattermost","epss":0.14,"enisaIdProduct":[{"id":"2b07a67e-3f63-310a-bf23-220e02c5dd03","product":{"name":"Mattermost","vendor":{"name":"Mattermost"}},"product_version":"10.11.0 ≤10.11.13"},{"id":"e5c8e9f5-08b0-3ff7-a68c-44cc06413cd5","product":{"name":"Mattermost","vendor":{"name":"Mattermost"}},"product_version":"11.5.0 ≤11.5.1"}],"enisaIdVendor":[{"id":"09f00dee-24a6-31a7-b873-540ffdb6d47a","vendor":{"name":"Mattermost"}}],"enisaIdVulnerability":[{"id":"3398902b-5aa2-3134-a7f2-c0a03056e579","vulnerability":{"id":"CVE-2026-6333","description":"Mattermost versions 11.5.x \u003c\u003d 11.5.1, 10.11.x \u003c\u003d 10.11.13 fail to validate the Host header when constructing response URLs for custom slash commands which allows an authenticated attacker to redirect slash command responses to an attacker-controlled server via a spoofed Host header.. Mattermost Advisory ID: MMSA-2026-00582","datePublished":"May 18, 2026, 8:41:29 AM","dateUpdated":"May 19, 2026, 5:19:42 PM","status":"PUBLISHED","baseScore":3.5,"baseScoreVersion":"3.1","baseScoreVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N","references":"https://mattermost.com/security-updates\n","enisa_id":"EUVD-2026-30755\n","assigner":"Mattermost","epss":0.14,"dataProcessed":"Nov 9, 2026, 7:17:04 AM","vulnerabilityProduct":[{"id":"1e7f0e10-9786-3194-8c19-1f319295aeb5","product":{"name":"Mattermost","vendor":{"name":"Mattermost"}},"product_version":"11.5.0 ≤11.5.1"},{"id":"2cdd7203-da5e-3a9c-9472-d5b4fe64a16b","product":{"name":"Mattermost","vendor":{"name":"Mattermost"}},"product_version":"10.11.0 ≤10.11.13"}],"vulnerabilityVendor":[{"id":"10800ef5-39ce-366b-ae21-5c3d8aef5b7a","vendor":{"name":"Mattermost"}}]}},{"id":"da563265-143d-3690-9c61-b00d84b05a55","vulnerability":{"id":"GHSA-vqp5-2mrp-qqxg","description":"Mattermost doesn\u0027t validate the Host header when constructing response URLs for custom slash command","datePublished":"May 18, 2026, 9:31:48 AM","dateUpdated":"Jun 1, 2026, 3:29:47 PM","baseScore":0.0,"references":"https://nvd.nist.gov/vuln/detail/CVE-2026-6333\nhttps://github.com/mattermost/mattermost/commit/e738016c592045e14bf926eafaeda6f8521def6d\nhttps://github.com/mattermost/mattermost\nhttps://mattermost.com/security-updates\n","enisa_id":"EUVD-2026-30755\n","aliases":"CVE-2026-6333\nGHSA-vqp5-2mrp-qqxg\n","epss":0.0,"dataProcessed":"Nov 9, 2026, 3:48:27 PM","vulnerabilityProduct":[],"vulnerabilityVendor":[]}}],"enisaIdAdvisory":[]}