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How the mentioned CVE works:
The vulnerability exists in the sandbox noVNC helper route of openclaw versions between 2026.2.21 and before 2026.4.10. This route is intended to assist with noVNC (WebSocket-based VNC client) sessions inside a sandboxed environment. Normally, access to this helper should be gated behind bridge authentication, which verifies that the requesting user or service has proper permissions. However, due to a missing authentication check, the route was exposed directly. An unauthenticated attacker could reach the /sandbox/noVNC/helper endpoint without any valid bridge credentials. Once accessed, the helper route leaks interactive browser session credentials – specifically, the session tokens or cookies that allow a live, authenticated browser session to be hijacked. This is particularly dangerous because noVNC sessions often contain sensitive GUI interactions, terminal access, or administrative panels. The attacker could replay the captured credentials to take over the victim’s active browser session, bypassing login forms, multi-factor authentication, and other per-session protections. The flaw stems from improper routing middleware ordering: the helper route was registered before the bridge authentication middleware in the request pipeline. Thus, requests to that specific path never triggered the authentication logic. The fix, implemented in commit 8dfbf3268bd224b7377d1ecca77a445100746085 and PR 63882, moves the route registration after the authentication middleware or explicitly adds an authentication gate to the helper. Patched versions start at openclaw 2026.4.10, with full fix included in npm release 2026.4.14.
DailyCVE form:
Platform: npm openclaw
Version: 2026.2.21-2026.4.9
Vulnerability: Auth bypass leak
Severity: Critical
date: 2026-04-17
Prediction: Patch date 2026-04-10
What Undercode Say:
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Count vulnerable versions in npm registry npm view openclaw versions --json | jq '.[] | select(. >= "2026.2.21" and . < "2026.4.10")' | wc -l Check if your installed version is vulnerable npm list openclaw | grep openclaw@ && echo "Check version" Simulate unauthenticated access to the vulnerable route curl -k https://target:6080/sandbox/noVNC/helper -I
How Exploit:
1. Identify target with vulnerable openclaw 2. Send GET request to exposed helper route curl -s https://victim.com/sandbox/noVNC/helper | grep -E "session|token|cookie" 3. Extract WebSocket session credentials from response 4. Use stolen token in browser devtools or curl curl -H "Cookie: session=stolen_value" https://victim.com/api/private 5. Hijack noVNC session by connecting to ws://victim.com/websockify
Protection from this CVE:
- Upgrade to openclaw >= 2026.4.10 immediately: `npm install [email protected]`
– If cannot upgrade, apply reverse proxy rule to block/sandbox/noVNC/helper:location /sandbox/noVNC/helper { deny all; } - Enforce bridge authentication on all sandbox routes via middleware ordering.
- Monitor logs for GET requests to `/sandbox/noVNC/helper` from unexpected IPs.
Impact:
Full compromise of interactive browser sessions within the sandbox. Attackers gain same permissions as the victim user, including file access, command execution, and lateral movement to connected systems. No prior authentication required. Exposure of session credentials leads to account takeover without triggering login alerts.
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Sources:
Reported By: github.com
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