CVE-2026-126072

Not enough EPSS history yet.

Action Pack is a framework for handling and responding to web requests. Prior to 8.1.4.1 and 8.0.5.2, ActionController::Live::Buffer#close pushes its end-of-stream marker onto the response's bounded queue while it holds the buffer's monitor. When the client has stopped reading and the queue is full, the push blocks, and Buffer#abort, which runs when the client disconnects or a write times out, waits indefinitely for the same monitor. Each such response could permanently hold a web server thread and its ActionController::Live thread, possibly resulting in a DoS vulnerability through thread exhaustion. Applications that stream responses with ActionController::Live, including send_stream, are affected. Applications that serve large files through Active Storage proxy mode are exposed to unauthenticated clients. This issue is fixed in versions 8.1.4.1 and 8.0.5.2.

• github.comhttps://github.com/rails/rails/commit/27ad18ed5900dee28ba20e9c6fc718ff751fa215
• github.comhttps://github.com/rails/rails/commit/ccbfc09690fef05fdd2a9969c917a71b92cc98fc
• github.comhttps://github.com/rails/rails/releases/tag/v8.0.5.2
• github.comhttps://github.com/rails/rails/releases/tag/v8.1.4.1
• github.comhttps://github.com/rails/rails/security/advisories/GHSA-rwvh-fw6r-pwvp