CVE-2026-55876

Description

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.

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Produits concernés

• HeliumEdu platform

Scores CVSS

Faiblesses (CWE)

• CWE-79

Références

• https://github.com/HeliumEdu/platform/commit/f0de5c985c701942758b805a3d11dfb008a6af88
• https://github.com/HeliumEdu/platform/security/advisories/GHSA-7r65-76fw-ch5c
• https://github.com/HeliumEdu/platform/security/advisories/GHSA-7r65-76fw-ch5c

Ailleurs

• NVD
• CVE.org
• CIRCL Vulnerability-Lookup
• CERT-FR
• GitHub Advisories