nanobot: Missing Origin Validation in WebSockets
CVE-2026-35589 is a critical-severity missing origin validation in websockets vulnerability in nanobot from HKUDS, with a CVSS 3.1 base score of 9.3 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. Affected nanobot versions: < 0.1.5. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.16% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of nanobot you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.0 | High | CNA (github.com) |
| CVSS 3.1 | 9.3 | Critical | NVD |
Official description
nanobot is a personal AI assistant. Versions prior to 0.1.5 contain a Cross-Site WebSocket Hijacking (CSWSH) vulnerability exists in the bridge's WebSocket server in bridge/src/server.ts, resulting from an incomplete remediation of CVE-2026-2577. The original fix changed the binding from 0.0.0.0 to 127.0.0.1 and added an optional BRIDGE_TOKEN parameter, but token authentication is disabled by default and the server does not validate the Origin header during the WebSocket handshake. Because browsers do not enforce the Same-Origin Policy on WebSockets unless the server explicitly denies cross-origin connections, any website visited by a user running the bridge can establish a WebSocket connection to ws://127.0.0.1:3001/ and gain full access to the bridge API. This allows an attacker to hijack the WhatsApp session, read incoming messages, steal authentication QR codes, and send messages on behalf of the user. This issue has bee fixed in version 0.1.5.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Missing Origin Validation in WebSockets
The product uses a WebSocket, but it does not properly verify that the source of data or communication is valid.
How developers prevent this class of flaw
- Enable CORS-like access restrictions by verifying the 'Origin' header during the WebSocket handshake.
- Use a randomized CSRF token to verify requests.
- Use TLS to securely communicate using 'wss' (WebSocket Secure) instead of 'ws'.
More Missing Origin Validation in WebSockets vulnerabilities (CWE-1385)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
- github.com/HKUDS/nanobot/releases/tag/v0.1.5Product, Release Notes
Other vulnerabilities in nanobot
- 8.6 High severity
- 7.3 High severity
- 8.7 High severity
- 7.0 High severity
- 9.8 Critical severity
- 10.0 Critical severity
Recent Missing Origin Validation in WebSockets vulnerabilities
- 8.1 High severity
- 8.8 High severity
- 8.8 High severity
- 9.4 Critical severity
- 9.8 Critical severity
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