---
id: "CVE-2026-125361"
page: "https://infrastack.ai/live/CVE-2026-125361"
kind: "vulnerability"
aliases: ["CVE-2026-125361"]
title: "Tencent BrowserSkill: local attacker impersonates daemon and runs JavaScript in browser tabs"
severity: "high"
cvss: 7.2
epss: null
exploited: false
status: "open"
category: "ai-tooling"
products: [{"name": "BrowserSkill", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["ai-agents", "ai-tooling", "browserskill", "cdp", "local-dev"]
not_affected_if: ["not-installed", "version-above-0.4.2"]
published_at: "2026-11-10T00:17:07+00:00"
first_seen_at: "2026-11-10T00:28:42+00:00"
updated_at: "2026-11-10T00:30:06+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-125361", "first_seen_at": "2026-11-10T00:28:42+00:00"}]
exploit_sources: []
---

# Tencent BrowserSkill: local attacker impersonates daemon and runs JavaScript in browser tabs

Link for people: https://infrastack.ai/live/CVE-2026-125361 (this .md is for agents)

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.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:BrowserSkill affected range not listed fixed no fixed version listed

## How to check

- Check whether BrowserSkill is installed and which version is present, for example by reading its package manifest or the installed extension's version.
- Look for a `bsk` daemon listening on a loopback WebSocket port on developer machines and servers that run the tool.

## Fix

- Move to a BrowserSkill release later than `0.4.2`; the sources do not name the fixed version in the product ranges.

## Timeline

- 2026-11-10T00:28:42+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-125361

## Documents

- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/tencent-browserskill-through-0.4.2-missing-authentication-in-local-websocket-transport
- [fix] Patch: github.com https://github.com/Tencent/BrowserSkill/commit/7e862a44d19d0c1e492901fe29562cc7d79af590

## From the sources

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.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_