--- title: GHSA-r766-3v88-pfcf (where_is_waldo): where_is_waldo... description: A security advisory (GHSA-r766-3v88-pfcf) discloses an authentication bypass vulnerability in the `where_is_waldo` Ruby gem. When no `authenticate_proc` is... canonical: https://daily.dev/posts/ghsa-r766-3v88-pfcf-where-is-waldo-where-is-waldo-authenticates-actioncable-connections-from-a-cl-xfttjrqdx twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: GHSA-r766-3v88-pfcf (where_is_waldo): where_is_waldo authenticates ActionCable connections from a client-supplied subject_id when no authenticate_proc is configured | daily.dev og:description: A security advisory (GHSA-r766-3v88-pfcf) discloses an authentication bypass vulnerability in the `where_is_waldo` Ruby gem. When no `authenticate_proc` is... og:url: https://daily.dev/posts/ghsa-r766-3v88-pfcf-where-is-waldo-where-is-waldo-authenticates-actioncable-connections-from-a-cl-xfttjrqdx og:image: https://api.daily.dev/og/posts/xftTJRQdX.png og:image:alt: GHSA-r766-3v88-pfcf (where_is_waldo): where_is_waldo authenticates ActionCable connections from a client-supplied subject_id when no authenticate_proc is configured og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # GHSA-r766-3v88-pfcf (where_is_waldo): where_is_waldo authenticates ActionCable connections from a client-supplied subject_id when no authenticate_proc is configured **[RUBYLAND](https://daily.dev/sources/rubyla)** · 1 min read · 0 upvotes · 0 comments ## Summary A security advisory (GHSA-r766-3v88-pfcf) discloses an authentication bypass vulnerability in the `where_is_waldo` Ruby gem. When no `authenticate_proc` is configured, the gem's built-in ActionCable connection authenticates using a client-supplied `subject_id` query parameter, allowing any client to impersonate arbitrary subjects and access cross-account presence roster data (CWE-290). Only apps using the built-in connection without `authenticate_proc` are affected. The issue is fixed in version 0.1.6, which restricts the params-based auth path to local development and test environments only. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Push subscriptions can be abused for server-side requests](https://daily.dev/posts/push-subscriptions-can-be-abused-for-server-side-requests-2abqub7mp) · RUBYLAND · 0 upvotes · 0 comments - [Build an IDOR Vulnerability Lab: Why WHERE Clauses Don’t Protect Your API.](https://daily.dev/posts/build-an-idor-vulnerability-lab-why-where-clauses-don-t-protect-your-api--wmreqolv5) · InfoSec Write-ups · 0 upvotes · 0 comments - [GHSA-prq8-7wvh-44qh \(oauth\): Cross-origin OAuth token-request redirects can expose signed request metadata](https://daily.dev/posts/ghsa-prq8-7wvh-44qh-oauth-cross-origin-oauth-token-request-redirects-can-expose-signed-request-me-ktjgrr4kt) · RUBYLAND · 0 upvotes · 0 comments - [Exploring Rails Action Cable with Solid Cable](https://daily.dev/posts/exploring-rails-action-cable-with-solid-cable-fgtpdoax5) · Honeybadger · 0 upvotes · 0 comments --- Tags: [#security](https://daily.dev/tags/security), [#authentication](https://daily.dev/tags/authentication), [#ruby](https://daily.dev/tags/ruby) [View this post on daily.dev](https://daily.dev/posts/ghsa-r766-3v88-pfcf-where-is-waldo-where-is-waldo-authenticates-actioncable-connections-from-a-cl-xfttjrqdx) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"GHSA-r766-3v88-pfcf (where_is_waldo): where_is_waldo authenticates ActionCable connections from a client-supplied subject_id when no authenticate_proc is configured","url":"https://daily.dev/posts/ghsa-r766-3v88-pfcf-where-is-waldo-where-is-waldo-authenticates-actioncable-connections-from-a-cl-xfttjrqdx","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/ghsa-r766-3v88-pfcf-where-is-waldo-where-is-waldo-authenticates-actioncable-connections-from-a-cl-xfttjrqdx"},"datePublished":"2026-07-25T18:22:32.243Z","dateModified":"2026-07-25T18:22:49.014Z","description":"A security advisory (GHSA-r766-3v88-pfcf) discloses an authentication bypass vulnerability in the `where_is_waldo` Ruby gem. 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