Description

Heptabase developed by Hepta Platforms, Inc. has a Stored Cross-Site Scripting vulnerability. Authenticated remote attackers can inject persistent malicious content into specific pages, causing arbitrary JavaScript code to execute when other users click the crafted content.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.7",
  "pubDate": "2026-08-24T04:16:59.817Z",
  "pubdate": "2026-08-24T04:16:59.817Z",
  "executiveSummary": "Heptabase, developed by Hepta Platforms, Inc., suffers from a Stored Cross-Site Scripting (XSS) vulnerability. This security flaw allows authenticated remote attackers to inject persistent malicious content, specifically arbitrary JavaScript code, directly into targeted pages within the application. When other users navigate to or interact with the crafted content, the injected script executes within the context of the victim's browser session.\nThe primary impact of this vulnerability includes session hijacking, unauthorized access to sensitive user data, and the potential execution of unintended actions on behalf of the authenticated victim. The attack requires remote authentication and the ability to inject data into specific application pages that lack proper input sanitization and output encoding. The risk implication is significant as it compromises the confidentiality and integrity of user sessions within the affected product.",
  "technicalDetails": "The root cause of the vulnerability stems from insufficient input sanitization and improper output encoding of user-supplied data before it is stored within the application database and subsequently rendered to other users. This architectural flaw characterizes a classic Stored Cross-Site Scripting (XSS) vector.\nExploitation requires the attacker to possess authenticated remote access to the Heptabase platform. With valid credentials, the attacker crafts and injects persistent malicious payloads containing arbitrary JavaScript code into specific application pages or components.\nThe attack flow proceeds as follows: First, the authenticated attacker submits a crafted HTTP request containing the malicious JavaScript payload to the vulnerable application endpoint. Second, the backend application stores this untrusted input persistently within the data store without performing adequate sanitization or structural validation. Third, when a victim user navigates to the affected page, the application retrieves the stored malicious content and renders it within the Document Object Model (DOM) of the victim's browser.\nBecause the application fails to apply context-aware output encoding, the browser interprets the injected payload as executable script rather than inert text data. Consequently, the arbitrary JavaScript code executes in the security context of the victim's active session, allowing the attacker to inherit the victim's permissions and privileges within the application.\nPost-exploitation impact includes the potential extraction of session tokens, leakage of confidential workspace data, unauthorized modifications to user content, and further client-side compromise. The vulnerability affects the web-based components of Heptabase where user-generated content is persistently stored and displayed to multiple users."
}