CVE-2026-61613CWE-306

Cursor: Cloud Agent Browser Sandbox Escape

High · published July 15, 2026

CVSS v4.0
7.7
EPSS
1%
Percentile
51.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
7.7 · HIGH
Vector
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
EPSS
0.00678 · 51.7th percentile
Weakness
CWE-306 · Missing Authentication for Critical Function
Published
2026-07-15T14:18Z
EPSS history
Timeline
  • 15 JUL 14:18Z
    Cursor: Cloud Agent Browser Sandbox Escape
    cvelistv5