Description
Cursor is a code editor built for programming with AI. Prior to the Cloud Agent fix on 03/31/2026, browser-enabled Cursor Cloud Agent sessions allowed attacker-controlled web content to connect from inside the agent container to an unauthenticated local agent endpoint, enabling code execution within the affected Cloud Agent sandbox or session and access to files, repository contents, environment variables, credentials, and GitHub App access tokens available to that session. This issue was fixed on 03/31/2026 by requiring authentication for the relevant agent endpoint.
References1
Metrics
- CVSS 4.0
-
7.7
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 1% percentile: 53 · as of 15 November 2026
- CWE
- CWE-306
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.