{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/mattermost-server-11.6.x/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Mattermost Desktop App (5.13.x)","Mattermost Desktop App (6.x)","Mattermost Server (10.11.x)","Mattermost Server (11.5.x)","Mattermost Server (11.6.x)"],"_cs_severities":["medium"],"_cs_tags":["mattermost","vulnerability","unspecified"],"_cs_type":"advisory","_cs_vendors":["Mattermost"],"content_html":"\u003cp\u003eMultiple vulnerabilities have been discovered in Mattermost products as of May 2026. The vulnerabilities affect Mattermost Desktop App versions prior to 5.13.6, versions prior to 6.2, and Mattermost Server versions 10.11.x prior to 10.11.17, 11.5.x prior to 11.5.5, and 11.6.x prior to 11.6.2. These vulnerabilities allow an attacker to trigger unspecified security issues, posing a risk to organizations using these versions of Mattermost. The vendor has not provided specific details regarding the nature of these vulnerabilities. Defenders should prioritize patching.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003cp\u003eDue to the lack of specific vulnerability information, a generic attack chain is provided. This chain assumes a vulnerability allowing for remote code execution.\u003c/p\u003e\n\u003col\u003e\n\u003cli\u003eAttacker identifies a vulnerable Mattermost instance (Desktop App or Server) through reconnaissance.\u003c/li\u003e\n\u003cli\u003eAttacker crafts a malicious payload tailored to exploit the unspecified vulnerability.\u003c/li\u003e\n\u003cli\u003eAttacker delivers the payload to the Mattermost instance (e.g., via a crafted message, API call, or file upload).\u003c/li\u003e\n\u003cli\u003eThe vulnerable Mattermost component processes the malicious payload, leading to code execution.\u003c/li\u003e\n\u003cli\u003eAttacker gains initial access to the system running the Mattermost instance.\u003c/li\u003e\n\u003cli\u003eAttacker performs privilege escalation to gain higher-level access.\u003c/li\u003e\n\u003cli\u003eAttacker moves laterally within the network, potentially targeting other systems or data.\u003c/li\u003e\n\u003cli\u003eAttacker achieves their objective, such as data exfiltration, system compromise, or service disruption.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of these vulnerabilities could lead to a range of impacts, including unauthorized access to sensitive data, compromise of Mattermost servers and desktop applications, and potential lateral movement within the affected network. The lack of specifics from the vendor makes it difficult to assess the precise impact, but organizations should assume a potential for significant damage.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eUpgrade Mattermost Desktop App to version 5.13.6 or later, or version 6.2 or later, to remediate the vulnerabilities affecting the desktop application.\u003c/li\u003e\n\u003cli\u003eUpgrade Mattermost Server to version 10.11.17 or later, 11.5.5 or later, or 11.6.2 or later, to remediate the vulnerabilities affecting the server.\u003c/li\u003e\n\u003cli\u003eMonitor network traffic for suspicious activity originating from or directed towards Mattermost servers, as a compensating control.\u003c/li\u003e\n\u003cli\u003eEnable verbose logging on Mattermost servers and desktop applications to facilitate incident response and investigation.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-19T12:12:19Z","date_published":"2026-05-19T12:12:19Z","id":"https://feed.craftedsignal.io/briefs/2026-05-mattermost-vulns/","summary":"Multiple unspecified vulnerabilities in Mattermost Desktop App and Mattermost Server allow an attacker to cause an unspecified security issue.","title":"Multiple Vulnerabilities in Mattermost Products","url":"https://feed.craftedsignal.io/briefs/2026-05-mattermost-vulns/"}],"language":"en","title":"CraftedSignal Threat Feed — Mattermost Server (11.6.x)","version":"https://jsonfeed.org/version/1.1"}