{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","favicon":"https://feed.craftedsignal.io/favicon-32x32.png","feed_url":"https://feed.craftedsignal.io/products/mattermost-10.11.21/feed.json","home_page_url":"https://feed.craftedsignal.io/","icon":"https://feed.craftedsignal.io/apple-touch-icon.png","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":8.3,"id":"CVE-2026-9816"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Mattermost (10.11.21)","Mattermost (11.7.6)","Mattermost (11.8.3)"],"_cs_severities":["high"],"_cs_tags":["vulnerability-management","security-advisory","patch-management"],"_cs_type":"advisory","_cs_vendors":["Mattermost"],"content_html":"\u003cp\u003eMattermost has issued a security advisory (AV26-828) identifying vulnerabilities impacting multiple product versions, specifically those prior to or equal to 10.11.21, 11.7.6, and 11.8.3. The advisory highlights the necessity of addressing CVE-2026-9816 to protect the platform from potential exploitation. Organizations running affected Mattermost server instances should consult the vendor's official security updates page to identify specific remediation steps and version requirements. As this is a vendor-published vulnerability notice, prompt patching is recommended to maintain the security posture of the collaboration environment.\u003c/p\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of vulnerabilities in enterprise collaboration software like Mattermost can lead to unauthorized information disclosure, privilege escalation, or potential remote code execution depending on the specific nature of the vulnerability. Organizations relying on Mattermost for internal communications are at risk of data exfiltration and potential compromise of sensitive internal discussions if these versions remain unpatched.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cp\u003ePrioritized actions for security and IT teams:\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eAudit all Mattermost server installations to identify versions 10.11.21, 11.7.6, 11.8.3, or earlier.\u003c/li\u003e\n\u003cli\u003eReview the official Mattermost Security Updates page for specific patching instructions associated with CVE-2026-9816.\u003c/li\u003e\n\u003cli\u003ePrioritize patching for internet-facing Mattermost server instances immediately.\u003c/li\u003e\n\u003cli\u003eValidate patch installation by confirming the server version meets the vendor's security requirements post-deployment.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-08-18T20:53:30Z","date_published":"2026-08-18T20:53:30Z","id":"https://feed.craftedsignal.io/briefs/2026-08-mattermost-advisory/","summary":"Mattermost has released critical security patches for multiple versions to address vulnerabilities tracked under CVE-2026-9816.","title":"Mattermost Security Update for CVE-2026-9816","url":"https://feed.craftedsignal.io/briefs/2026-08-mattermost-advisory/"}],"language":"en","title":"CraftedSignal Threat Feed - Mattermost (10.11.21)","version":"https://jsonfeed.org/version/1.1"}