CVE-2026-55876

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-55876", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-06-17T16:59:42.759Z", "datePublished": "2026-10-15T17:23:07.781Z", "dateUpdated": "2026-10-21T01:01:03.086Z"}, "containers": {"cna": {"title": "Helium: Stored XSS via Unrestricted SVG File Upload \u2014 Authenticated Users Can Store Executable Scripts", "problemTypes": [{"descriptions": [{"cweId": "CWE-79", "lang": "en", "description": "CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 3.5, "baseSeverity": "LOW", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N", "version": "3.1"}}], "references": [{"name": "https://github.com/HeliumEdu/platform/security/advisories/GHSA-7r65-76fw-ch5c", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/HeliumEdu/platform/security/advisories/GHSA-7r65-76fw-ch5c"}, {"name": "https://github.com/HeliumEdu/platform/commit/f0de5c985c701942758b805a3d11dfb008a6af88", "tags": ["x_refsource_MISC"], "url": "https://github.com/HeliumEdu/platform/commit/f0de5c985c701942758b805a3d11dfb008a6af88"}], "affected": [{"vendor": "HeliumEdu", "product": "platform", "versions": [{"version": "< 2.2.60", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-10-15T17:23:07.781Z"}, "descriptions": [{"lang": "en", "value": "Helium is a free online student planner for classes, homework, grades, and notes. Prior to 2.2.60, the POST /planner/attachments/ endpoint allows authenticated users to upload SVG and HTML attachments because conf/configs/common.py omits those formats from BLOCKED_ATTACHMENT_EXTENSIONS and BLOCKED_ATTACHMENT_MIME_TYPES, and helium/planner/serializers/attachmentserializer.py relies on those blocklists. An uploaded SVG served as image/svg+xml can execute embedded script when a visitor opens its public attachment URL, allowing persistent attacker-controlled active content and phishing under an application-managed storage URL. The attachment storage uses a separate origin from the application, so same-origin policy prevents the script from reading application cookies or storage, and application-session compromise is not supported by the maintained deployment configuration. This issue is fixed in version 2.2.60."}], "source": {"advisory": "GHSA-7r65-76fw-ch5c", "discovery": "UNKNOWN"}}, "adp": [{"references": [{"url": "https://github.com/HeliumEdu/platform/security/advisories/GHSA-7r65-76fw-ch5c", "tags": ["exploit"]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-10-21T01:00:34.594595Z", "id": "CVE-2026-55876", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-21T01:01:03.086Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-55876", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-21T01:00:34.594595Z"}}}], "references": [{"url": "https://github.com/HeliumEdu/platform/security/advisories/GHSA-7r65-76fw-ch5c", "tags": ["exploit"]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-21T01:00:54.788Z"}}], "cna": {"title": "Helium: Stored XSS via Unrestricted SVG File Upload \u2014 Authenticated Users Can Store Executable Scripts", "source": {"advisory": "GHSA-7r65-76fw-ch5c", "discovery": "UNKNOWN"}, "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 3.5, "attackVector": "NETWORK", "baseSeverity": "LOW", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}}], "affected": [{"vendor": "HeliumEdu", "product": "platform", "versions": [{"status": "affected", "version": "< 2.2.60"}]}], "references": [{"url": "https://github.com/HeliumEdu/platform/security/advisories/GHSA-7r65-76fw-ch5c", "name": "https://github.com/HeliumEdu/platform/security/advisories/GHSA-7r65-76fw-ch5c", "tags": ["x_refsource_CONFIRM"]}, {"url": "https://github.com/HeliumEdu/platform/commit/f0de5c985c701942758b805a3d11dfb008a6af88", "name": "https://github.com/HeliumEdu/platform/commit/f0de5c985c701942758b805a3d11dfb008a6af88", "tags": ["x_refsource_MISC"]}], "descriptions": [{"lang": "en", "value": "Helium is a free online student planner for classes, homework, grades, and notes. Prior to 2.2.60, the POST /planner/attachments/ endpoint allows authenticated users to upload SVG and HTML attachments because conf/configs/common.py omits those formats from BLOCKED_ATTACHMENT_EXTENSIONS and BLOCKED_ATTACHMENT_MIME_TYPES, and helium/planner/serializers/attachmentserializer.py relies on those blocklists. An uploaded SVG served as image/svg+xml can execute embedded script when a visitor opens its public attachment URL, allowing persistent attacker-controlled active content and phishing under an application-managed storage URL. The attachment storage uses a separate origin from the application, so same-origin policy prevents the script from reading application cookies or storage, and application-session compromise is not supported by the maintained deployment configuration. This issue is fixed in version 2.2.60."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-79", "description": "CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-10-15T17:23:07.781Z"}}}, "cveMetadata": {"cveId": "CVE-2026-55876", "state": "PUBLISHED", "dateUpdated": "2026-10-21T01:01:03.086Z", "dateReserved": "2026-06-17T16:59:42.759Z", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "datePublished": "2026-10-15T17:23:07.781Z", "assignerShortName": "GitHub_M"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"product": "platform", "vendor": "HeliumEdu", "versions": [{"status": "affected", "version": "< 2.2.60"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Helium is a free online student planner for classes, homework, grades, and notes. Prior to 2.2.60, the POST /planner/attachments/ endpoint allows authenticated users to upload SVG and HTML attachments because conf/configs/common.py omits those formats from BLOCKED_ATTACHMENT_EXTENSIONS and BLOCKED_ATTACHMENT_MIME_TYPES, and helium/planner/serializers/attachmentserializer.py relies on those blocklists. An uploaded SVG served as image/svg+xml can execute embedded script when a visitor opens its public attachment URL, allowing persistent attacker-controlled active content and phishing under an application-managed storage URL. The attachment storage uses a separate origin from the application, so same-origin policy prevents the script from reading application cookies or storage, and application-session compromise is not supported by the maintained deployment configuration. This issue is fixed in version 2.2.60."}], "id": "CVE-2026-55876", "lastModified": "2026-10-21T01:17:39.250", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 3.5, "baseSeverity": "LOW", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 2.1, "impactScore": 1.4, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-55876", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-10-21T01:00:34.594595Z", "version": "2.0.3"}}]}, "published": "2026-10-15T18:17:28.307", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/HeliumEdu/platform/commit/f0de5c985c701942758b805a3d11dfb008a6af88"}, {"source": "security-advisories@github.com", "url": "https://github.com/HeliumEdu/platform/security/advisories/GHSA-7r65-76fw-ch5c"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "url": "https://github.com/HeliumEdu/platform/security/advisories/GHSA-7r65-76fw-ch5c"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,2.2.60)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "cna", "scores": [{"score": 100.0, "source": "cna"}]}, "original": {"product": "platform", "source": "cna", "vendor": "HeliumEdu"}, "product": "platform", "vendor": "heliumedu"}], "created": "2026-10-16T21:15:14.690220+00:00", "updated": "2026-10-26T22:37:01.413928+00:00", "vendors": ["heliumedu", "heliumedu$PRODUCT$platform"]}