BROWSERSKILL · CVE-2026-125361 · AI agents & MCP
NO FIX YET · SEE WHAT TO DO
Tencent BrowserSkill through 0.4.2 connects to a loopback WebSocket without credentials or peer verification, so a local process can pose as the bsk daemon. The attacker then receives the extension's full tool surface, including evaluate, which runs JavaScript through CDP in logged-in browser tabs.
first public Nov 10, 2026 · 1 source
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Anyone running Tencent BrowserSkill through 0.4.2 on a machine where other local users or processes can run code. The flaw needs a local attacker who binds the daemon port before or after the real daemon runs. Machines without BrowserSkill installed are not affected.
Not affected if not-installed, version-above-0.4.2
Who cares ai-agents, browserskill, cdp, local-dev
bsk daemon listening on a loopback WebSocket port on developer machines and servers that run the tool.0.4.2; the sources do not name the fixed version in the product ranges.Tencent BrowserSkill through 0.4.2 contains a missing authentication vulnerability that allows local attackers to impersonate the bsk daemon because remoteSocket() connects to the loopback WebSocket without credentials or peer verification. Attackers who bind the daemon port before it starts or after it exits receive the extension's full tool surface, including evaluate, to run JavaScript through CDP in logged-in browser tabs.
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