CVE-2026-67199 Perspective 5.0.0 DoS via Loop Expression Evaluation
Remote attackers can cause a denial of service in Perspective by submitting crafted expressions with unbounded loops, blocking the server event loop.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-67199?
CVE-2026-67199 is a high-severity denial of service vulnerability in perspective-dev perspective, published on 4 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-770
Which versions are affected by CVE-2026-67199?
How do I fix CVE-2026-67199?
No fix has been published for CVE-2026-67199 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-67199 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-67199 exists.
Sources
Also known as GHSA-vc2q-3q58-3rrv.