CVE-2026-54157 Overview
CVE-2026-54157 is a Server-Side Request Forgery (SSRF) vulnerability [CWE-918] in LobeHub, a collaborative agent-team workspace platform. The /webapi/proxy endpoint on app.lobehub.com accepts a URL in the POST body and fetches it server-side without authentication. Attackers can issue arbitrary outbound requests from LobeHub infrastructure, exfiltrate Vercel deployment metadata, and inject cookies on the lobehub.com domain through reflected Set-Cookie headers. The issue affects all versions prior to 2.1.57 and is patched in 2.1.57.
Critical Impact
Unauthenticated attackers can pivot through LobeHub's backend to reach internal services, leak deployment secrets, and tamper with user sessions across the lobehub.com domain.
Affected Products
- LobeHub versions prior to 2.1.57
- app.lobehub.com hosted service
- LobeHub deployments running on Vercel infrastructure
Discovery Timeline
- 2026-06-23 - CVE-2026-54157 published to NVD
- 2026-06-23 - Last updated in NVD database
Technical Details for CVE-2026-54157
Vulnerability Analysis
The /webapi/proxy endpoint functions as a server-side fetch proxy. It reads a URL from the POST body and performs the request from LobeHub's backend without validating the caller or the target. Because no authentication is enforced, any remote actor can drive outbound HTTP traffic from LobeHub's servers.
Three attack outcomes follow from this design. First, the attacker can probe internal services reachable from the Vercel runtime, including cloud metadata endpoints used by serverless functions. Second, response headers from arbitrary targets are reflected back to the client, allowing Set-Cookie values to be planted on the lobehub.com domain through the proxy response. Third, request fingerprints leak Vercel deployment identifiers that aid further reconnaissance.
Root Cause
The root cause is missing access control combined with absent URL validation on a proxying primitive. The endpoint trusts user-supplied URLs and forwards response metadata without filtering. This pattern is the canonical SSRF anti-pattern described in [CWE-918].
Attack Vector
Exploitation requires only network access to app.lobehub.com. An attacker sends a POST request to /webapi/proxy containing a target URL. The server fetches the URL and returns body and headers to the attacker. By choosing internal IP ranges, cloud metadata hosts, or attacker-controlled domains that reply with Set-Cookie, the attacker reaches non-public services or hijacks sessions on the LobeHub domain. No user interaction or credentials are required.
No public exploit code is referenced in the advisory. See the GitHub Security Advisory for upstream technical details.
Detection Methods for CVE-2026-54157
Indicators of Compromise
- POST requests to /webapi/proxy originating from unauthenticated sessions or unexpected source IPs.
- Outbound requests from LobeHub infrastructure to RFC1918 ranges, link-local addresses, or cloud metadata endpoints such as 169.254.169.254.
- Proxy responses containing Set-Cookie headers reflected from third-party hosts.
- Anomalous bursts of distinct URLs submitted to /webapi/proxy consistent with internal network scanning.
Detection Strategies
- Inspect web access logs for POST traffic to /webapi/proxy and correlate with downstream egress activity.
- Alert on egress connections from LobeHub workloads targeting private address space or cloud metadata services.
- Flag responses where headers from the upstream fetch include Set-Cookie values written to the lobehub.com scope.
Monitoring Recommendations
- Forward Vercel function logs and edge logs to a centralized analytics platform for retention and search.
- Baseline normal proxy traffic volume and alert on deviations in request rate or target diversity.
- Monitor for new cookies appearing on user sessions that did not originate from the authentication flow.
How to Mitigate CVE-2026-54157
Immediate Actions Required
- Upgrade LobeHub to version 2.1.57 or later immediately.
- Audit logs for /webapi/proxy activity since deployment and investigate any suspicious targets.
- Invalidate active user sessions and rotate any cookies issued on the lobehub.com domain during the exposure window.
- Rotate Vercel deployment secrets and review platform tokens that may have been exposed.
Patch Information
The vendor fixed the vulnerability in LobeHub 2.1.57. The patch and advisory are published at the LobeHub GitHub Security Advisory GHSA-xmwj-c75x-6346. Self-hosted operators must update their deployments; users of the hosted app.lobehub.com service receive the fix from the vendor.
Workarounds
- Block external access to /webapi/proxy at the edge until the upgrade is applied.
- Enforce egress filtering on LobeHub workloads to deny traffic to internal ranges and cloud metadata endpoints.
- Strip Set-Cookie from any responses returned by the proxy path via an intermediate reverse proxy or WAF rule.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
