๐Ÿ” CVE Alert

CVE-2026-126072

MEDIUM 5.9

Action Pack: Possible DoS vulnerability in Action Controller Live streaming

CVSS Score
5.9
EPSS Score
0.0%
EPSS Percentile
0th

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.

CWE CWE-833
Vendor rails
Product rails
Published Nov 10, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Affected Versions

rails / rails
>= 8.1, < 8.1.4.1 < 8.0.5.2

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
github.com: https://github.com/rails/rails/security/advisories/GHSA-rwvh-fw6r-pwvp github.com: https://github.com/rails/rails/commit/27ad18ed5900dee28ba20e9c6fc718ff751fa215 github.com: https://github.com/rails/rails/commit/ccbfc09690fef05fdd2a9969c917a71b92cc98fc github.com: https://github.com/rails/rails/releases/tag/v8.0.5.2 github.com: https://github.com/rails/rails/releases/tag/v8.1.4.1