Description

Altair is a GraphQL client for all platforms. From 7.2.4 until 8.5.8, packages/altair-iframe-sandbox/src/main.ts reads plugin_sandbox_opts from the iframe-sandbox query string and passes attacker-controlled scriptUrls to injectScript() in packages/altair-core/src/utils/inject.ts, which creates script elements in the page. The intended parent iframe flow places the page in an iframe with sandbox allow-scripts and without allow-same-origin, but direct navigation to a crafted iframe-sandbox URL omits that isolation and executes the supplied script in the origin serving Altair. Exploitation requires a victim to open the crafted URL, and the resulting script can access script-readable storage and make same-origin requests according to the deployment's authentication and cookie controls. This issue is fixed in version 8.5.8.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.1",
  "pubDate": "2026-11-05T21:18:35.267Z",
  "pubdate": "2026-11-05T21:18:35.267Z",
  "executiveSummary": "Altair versions 7.2.4 through 8.5.8 are susceptible to a Cross-Site Scripting (XSS) vulnerability arising from improper handling of query string parameters in the iframe-sandbox component.\nThe vulnerability allows an unauthenticated attacker to execute arbitrary JavaScript within the context of the Altair origin by directing a victim to a specially crafted URL.\nThis occurs because the application fails to restrict the provenance of scripts injected via the 'plugin_sandbox_opts' parameter when accessed outside of the intended iframe-based security boundary.\nThe impact is significant, as successful exploitation enables attackers to bypass intended origin isolation, potentially leading to unauthorized access to local storage, session cookies, and the ability to perform authenticated requests on behalf of the victim.\nExploitation requires social engineering to induce a victim into navigating to a malicious link.\nThe vulnerability has been addressed in version 8.5.8.",
  "technicalDetails": "The root cause of this vulnerability is an insecure implementation of script injection logic within 'packages/altair-iframe-sandbox/src/main.ts' and 'packages/altair-core/src/utils/inject.ts'.\nThe application processes the 'plugin_sandbox_opts' parameter from the URL query string and extracts 'scriptUrls', which are then passed directly to the 'injectScript()' utility function.\nThe 'injectScript()' function programmatically creates and appends HTML <script> elements to the DOM. Under normal intended operation, the Altair architecture expects the application to be rendered within an iframe utilizing the 'sandbox' attribute with 'allow-scripts' but specifically omitting 'allow-same-origin'. This configuration typically limits the execution context of the script to a unique origin, preventing access to the parent application's sensitive data.\nHowever, the implementation fails to enforce the presence of this security context. If a user navigates directly to the crafted URL, the browser executes the injected script within the full security context of the Altair application origin. Because the page is not isolated by the restrictive iframe sandbox attributes during direct navigation, the script operates with the full privileges of the host domain.\nThe attack flow begins when an attacker crafts a URL containing a malicious 'plugin_sandbox_opts' payload, specifying an external resource or attacker-controlled script URL. Upon the victim navigating to this URL, the 'main.ts' logic parses the malicious input and triggers the 'injectScript()' function.\nThe browser processes the dynamically created script tag, executing the arbitrary code in the context of the Altair origin. Post-exploitation, the attacker can leverage this execution context to access script-readable browser storage, exfiltrate sensitive data such as session tokens or credentials stored in cookies, and conduct unauthorized API requests that inherit the victim's authentication state.\nThis vulnerability highlights a failure to validate user-supplied input before using it to modify the DOM, combined with an over-reliance on external container security measures (iframes) that are not strictly enforced during direct URL navigation.\nThe flaw affects versions 7.2.4 through 8.5.8."
}