{"id":"CVE-2026-55875","published":"2026-10-15T18:17:28.130","lastModified":"2026-10-16T20:04:29.760","description":"Helium is a free online student planner for classes, homework, grades, and notes. Prior to 2.2.60, any authenticated user can submit an arbitrary URL to POST /feed/externalcalendars/, where helium/feed/services/icalexternalcalendarservice.py uses validate_url to check only URL syntax before passing the value to urllib.request.urlopen, and fetch_ical_conditional periodically refetches the stored URL. The server can therefore issue requests to attacker-selected external or internal hosts, while distinct responses, including an uncaught http.client.RemoteDisconnected condition for non-HTTP services, reveal internal host and port reachability. The supported impact is forced outbound requests and internal service reconnaissance; the advisory does not demonstrate secret retrieval because the relevant ECS credentials path is task-specific and unpredictable. This issue is fixed in version 2.2.60.","cvssScore":4.3,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","cwes":["CWE-918"],"vendors":[],"products":[],"references":[{"url":"https://github.com/HeliumEdu/platform/commit/f0de5c985c701942758b805a3d11dfb008a6af88","tags":[]},{"url":"https://github.com/HeliumEdu/platform/security/advisories/GHSA-2f83-94pv-v3f5","tags":[]},{"url":"https://github.com/HeliumEdu/platform/security/advisories/GHSA-2f83-94pv-v3f5","tags":[]}],"exploitRefs":[{"url":"https://github.com/HeliumEdu/platform/commit/f0de5c985c701942758b805a3d11dfb008a6af88","tags":[]},{"url":"https://github.com/HeliumEdu/platform/security/advisories/GHSA-2f83-94pv-v3f5","tags":[]},{"url":"https://github.com/HeliumEdu/platform/security/advisories/GHSA-2f83-94pv-v3f5","tags":[]}],"hasPoc":true,"ai":null}