{"id":"CVE-2026-55875","state":"PUBLISHED","title":"Helium: SSRF via External Calendar URL Allows Authenticated Users to Probe Internal Network","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.","publishedAt":"2026-10-15T17:24:00.931Z","updatedAt":"2026-10-15T17:48:20.682Z","severity":{"score":4.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["HeliumEdu platform"],"affected":[{"vendor":"HeliumEdu","product":"platform","versions":[{"version":"< 2.2.60","status":"affected"}]}],"references":["https://github.com/HeliumEdu/platform/security/advisories/GHSA-2f83-94pv-v3f5","https://github.com/HeliumEdu/platform/commit/f0de5c985c701942758b805a3d11dfb008a6af88"],"weaknesses":["CWE-918"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55875.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55875","state":"PUBLISHED","datePublished":"2026-10-15T17:24:00.931Z","dateUpdated":"2026-10-15T17:48:20.682Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-17T16:59:42.759Z"},"containers":{"cna":{"title":"Helium: SSRF via External Calendar URL Allows Authenticated Users to Probe Internal Network","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"HeliumEdu","product":"platform","versions":[{"version":"< 2.2.60","status":"affected"}]}],"references":[{"url":"https://github.com/HeliumEdu/platform/security/advisories/GHSA-2f83-94pv-v3f5","name":"https://github.com/HeliumEdu/platform/security/advisories/GHSA-2f83-94pv-v3f5","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/HeliumEdu/platform/commit/f0de5c985c701942758b805a3d11dfb008a6af88","name":"https://github.com/HeliumEdu/platform/commit/f0de5c985c701942758b805a3d11dfb008a6af88","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.3,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-918","lang":"en","description":"CWE-918: Server-Side Request Forgery (SSRF)","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-15T17:24:00.931Z"},"source":{"advisory":"GHSA-2f83-94pv-v3f5","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/HeliumEdu/platform/security/advisories/GHSA-2f83-94pv-v3f5","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-15T17:47:47.971513Z","id":"CVE-2026-55875","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-15T17:48:20.682Z"}}]}}}