Roo-Code EUVD-2026-67279

Exploitation requires the attacker to occupy a network-adjacent or network-path position between the victim developer's machine and the OAuth provider endpoint (consistent with AC:H in the CVSS 4.0 vector). The victim must have Roo-Code installed and must initiate or be mid-flight in an OAuth authentication flow through the Claude Code integration - this is the trigger that causes the cleartext transmission. No authentication or privileges are required of the attacker (PR:N). No user interaction beyond the normal OAuth login action is required. Limiting factors include the high attack complexity (network interception position is not trivially obtained outside of compromised Wi-Fi, corporate proxies, or ARP spoofing), the limited confidentiality impact (OAuth token scope determines downstream damage), and the requirement that the user actively use the OAuth feature rather than a pre-authenticated session.

The CVSS 4.0 score of 6.3 (Medium) with vector AV:N/AC:H/AT:N/PR:N/UI:N/VC:L reflects a network-reachable flaw requiring high attack complexity - consistent with the description characterizing exploitability as difficult, likely demanding a man-in-the-middle network position. Confidentiality impact is limited to the vulnerable system (VC:L) with no integrity or availability consequences, and no scope change to subsequent systems. The E:P supplemental metric confirms a public proof-of-concept exists, elevating real-world risk above theoretical. However, the most significant compounding risk factor is the product's end-of-life status: the vendor has archived the repository and will not issue a patch, leaving all users permanently exposed. The disclosure context notes multiple issues were reported to the vendor, who declined to remediate, so defenders cannot expect upstream resolution. EPSS data was not provided in the input and cannot be inferred. The limited blast radius (OAuth token exposure, not remote code execution) and high complexity prevent this from being a top-tier emergency, but the permanent no-patch status and public POC make it a genuine priority for any organization still running Roo-Code.

An attacker with a man-in-the-middle position on the network path between a developer's workstation and the OAuth provider intercepts the OAuth callback traffic from Roo-Code's oauth.ts handler. Because the token or authorization code is transmitted in cleartext, the attacker captures the OAuth credential without needing any authentication or special software beyond a network sniffer. The captured token can then be replayed to access the associated AI provider account or any resource scoped to that OAuth grant. The public POC on GitHub demonstrates this interception technique.