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.