CVE-2026-67199: Perspective 5.0.0 DoS via Loop Expression Evaluation
Perspective 5.0.0 contains a denial of service vulnerability that allows remote attackers to block the server event loop indefinitely by submitting a crafted expression containing unbounded for or while loop constructs in a TableMakeViewReq message. Attackers can embed an arbitrarily large iteration count in an expression column evaluated once per table row, causing the Tornado IOLoop to block without any iteration cap, deadline, or cancellation check, rendering the server unresponsive to all connected clients.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-67199?
The severity of CVE-2026-67199 is medium, rated at 6.5.
How does CVE-2026-67199 affect Tornado Perspective 5.0.0?
CVE-2026-67199 allows remote attackers to create a denial of service situation by blocking the server event loop indefinitely.
What kind of attack vectors are associated with CVE-2026-67199?
Attackers exploit CVE-2026-67199 by submitting crafted expressions containing unbounded loops in TableMakeViewReq messages.
Are there any known mitigations for CVE-2026-67199?
Currently, there are no specified mitigations for CVE-2026-67199, and users should seek to limit exposure to vulnerable systems.
What is the impact of CVE-2026-67199 on system availability?
CVE-2026-67199 can lead to complete denial of service, rendering the affected Tornado Perspective instance unavailable.