{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/open-event-server--1.19.1/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":7.5,"id":"CVE-2026-63101"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Open Event Server \u003c= 1.19.1"],"_cs_severities":["high"],"_cs_tags":["authentication-bypass","data-exfiltration","web-application","cve"],"_cs_type":"advisory","_cs_vendors":["Open Event"],"content_html":"\u003cp\u003eCVE-2026-63101 affects Open Event Server up to and including version 1.19.1, presenting a critical missing authentication vulnerability. This flaw enables unauthenticated attackers to bypass security controls and export the complete member roster of any group. The attack leverages specific API endpoints that lack proper authentication decorators, allowing unauthorized access to sensitive user data such as email addresses, names, join dates, and roles. Attackers can programmatically discover group IDs, trigger the export process, and retrieve the resulting CSV file containing the full member details. This vulnerability poses a significant risk of data exfiltration and privacy breaches for organizations utilizing affected versions of Open Event Server.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAttacker identifies an instance of Open Event Server.\u003c/li\u003e\n\u003cli\u003eAttacker enumerates sequential group IDs, potentially by brute-forcing numerical IDs for target organizations.\u003c/li\u003e\n\u003cli\u003eAttacker crafts and sends an unauthenticated HTTP POST request to the \u003ccode\u003e/api/groups/{groupID}/followers/export_csv\u003c/code\u003e endpoint, specifying a known or enumerated \u003ccode\u003egroupID\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eThe vulnerable Open Event Server processes the unauthenticated request, initiating a CSV export task for the specified group's member roster.\u003c/li\u003e\n\u003cli\u003eAttacker polls an unauthenticated task status endpoint (e.g., \u003ccode\u003e/api/export_tasks/{taskID}/status\u003c/code\u003e) using the \u003ccode\u003etaskID\u003c/code\u003e received from the previous export request, to monitor the completion status of the export job.\u003c/li\u003e\n\u003cli\u003eOnce the export task is completed, the task status response provides a download URL for the generated CSV file.\u003c/li\u003e\n\u003cli\u003eAttacker accesses the provided download URL to retrieve the CSV file, which contains the complete member roster including email addresses, names, join dates, and roles.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-63101 leads to the complete compromise and exfiltration of sensitive member data from affected Open Event Server instances. This includes personally identifiable information (PII) such as email addresses, full names, account creation dates, and assigned roles within groups. The exposure of this data can result in severe privacy violations, facilitate targeted phishing campaigns, social engineering attacks against organization members, and compliance failures under data protection regulations. The ease of exploitation, requiring no authentication, means a wide range of organizations using Open Event Server could be at risk of significant data breaches.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003ePatch CVE-2026-63101 immediately by upgrading Open Event Server to a version beyond 1.19.1 that addresses this vulnerability.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rules in this brief to your SIEM and tune for your environment to detect suspicious activity related to CVE-2026-63101.\u003c/li\u003e\n\u003cli\u003eMonitor web server logs for HTTP POST requests to \u003ccode\u003e/api/groups/*/followers/export_csv\u003c/code\u003e and HTTP GET requests to \u003ccode\u003e/api/export_tasks/*/status\u003c/code\u003e without associated authentication tokens or session IDs.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-07-17T17:23:59Z","date_published":"2026-07-17T17:23:59Z","id":"https://feed.craftedsignal.io/briefs/2026-07-open-event-server-auth-bypass/","summary":"An authentication bypass vulnerability, CVE-2026-63101, in Open Event Server through version 1.19.1 allows unauthenticated attackers to export the complete member roster of any group by exploiting unauthenticated CSV export and task status endpoints, leading to the exfiltration of sensitive data like email addresses, names, and roles.","title":"Open Event Server Authentication Bypass for Member Roster Export (CVE-2026-63101)","url":"https://feed.craftedsignal.io/briefs/2026-07-open-event-server-auth-bypass/"}],"language":"en","title":"CraftedSignal Threat Feed - Open Event Server \u003c= 1.19.1","version":"https://jsonfeed.org/version/1.1"}