CVE-2026-125361
Tencent BrowserSkill through 0.4.2 Missing Authentication in Local WebSocket Transport
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.
Fixes and workarounds
Fix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: VulnCheckAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| BrowserSkill Tencent browser-skill
npm |
≥ 0; ≤ 0.4.2 (affected, semver)
Other versions: unaffected |
CNA: VulnCheck |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 7.2 high |
CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N | CNA: VulnCheck |
| 3.1 / 6.3 medium |
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N | CNA: VulnCheck |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/Tencent/BrowserSkill/issues/402CNA: VulnCheck · issue-tracking
- https://github.com/Tencent/BrowserSkillCNA: VulnCheck · product
- https://github.com/Tencent/BrowserSkill/blob/ext-v0.4.2/apps/extension/src/transport/remote-endpoint.ts#L79-L85CNA: VulnCheck · technical-description
- https://github.com/Tencent/BrowserSkill/commit/7e862a44d19d0c1e492901fe29562cc7d79af590CNA: VulnCheck · patch
- https://www.vulncheck.com/advisories/tencent-browserskill-through-0.4.2-missing-authentication-in-local-websocket-transportCNA: VulnCheck · third-party-advisory
For agents and automation
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Endpoints and access details
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