| Package | Affected versions | Patched versions |
|---|---|---|
| langflow | < 1.10.3 | 1.10.3 |
| langflow-base | < 0.10.3 | 0.10.3 |
| lfx | < 1.10.3 | 1.10.3 |
| lfx-docling | < 0.1.2 | 0.1.2 |
Before Langflow 1.10.3, several built-in components sent server-side HTTP requests to URLs the flow author controls, with no SSRF enforcement. An authenticated user who can build or run flows could make the Langflow server reach loopback, RFC 1918 / private networks, link-local addresses and cloud metadata endpoints (for example http://169.254.169.254/latest/meta-data/), and in many cases read the response back through the component output.
Two things combined to cause this:
lfx/utils/ssrf_protection.py, added in 1.7.0 by #10544) shipped with ssrf_protection_enabled = False, and its only caller, the API Request component, called validate_url_for_ssrf(url, warn_only=True). So even with protection turned on, blocked URLs were only logged.The problem was fixed across several PRs and is fully fixed in Langflow 1.10.3 (and 1.11.0+). With the default settings, outbound requests from these components are now validated after DNS resolution, pinned to the validated IP (to prevent DNS rebinding) and blocked when they target private, loopback, link-local or metadata addresses, unless the operator allowlists the host.
| Package (PyPI) | Vulnerable | Patched |
|---|---|---|
langflow | < 1.10.3 | 1.10.3 |
langflow-base | < 0.10.3 | 0.10.3 |
lfx | < 1.10.3 | 1.10.3 |
lfx-docling (Docling Serve component) | < 0.1.2 | 0.1.2 |
How the fix rolled out:
| Release | Change |
|---|---|
< 1.7.0 | No SSRF guard. All URL-taking components make unrestricted requests. |
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Scan my site free1.7.0 – 1.9.2 |
Guard exists, but ssrf_protection_enabled=False by default and API Request uses warn_only=True. |
1.9.3 | #13016: protection on by default, API Request blocks (DNS pinning / anti-rebinding). Other components still unprotected. |
1.10.1 | #13395 (RSS Reader, SearXNG) and #13643 (Home Assistant, Glean, plus model-provider URL components) route requests through SSRF-safe helpers. |
1.10.3 | #14033 (Docling Serve) and #14071 (Web Search result/RSS fetching). All components cited in this report are protected. |
Vulnerable pattern (for example rss.py before #13395):
response = requests.get(self.rss_url, timeout=self.timeout)
API Request before #13016:
# TODO: In next major version (2.0), remove warn_only=True to enforce blocking
validate_url_for_ssrf(url, warn_only=True)
with ssrf_protection_enabled: bool = False in the settings.
Clarifications on the original report. Some sinks in the report are not exploitable SSRF:
web_search.py: the DuckDuckGo search request and the Google News RSS request, and news_search.py:131. The host is hard-coded (html.duckduckgo.com / news.google.com) and user input only goes into quote_plus-encoded path and query segments, so the destination cannot be redirected. The real Web Search sink was fetching the result URLs, which is fixed in #14071.langflow/load/utils.py get_flow(): this is a client-side SDK helper (from langflow.load import get_flow) that the caller runs against their own Langflow URL. No API route calls it, so it is not a backend SSRF endpoint.http://169.254.169.254/latest/meta-data/ (or an internal host such as http://10.0.0.1/).On patched versions the same run fails with SSRFProtectionError: Access to IP address 169.254.169.254 is blocked by SSRF protection.
#13016: sets ssrf_protection_enabled = True by default, changes warn_only to default False, drops warn_only=True from API Request, and adds validate_and_resolve_url() plus SSRFProtectedTransport (DNS pinning).
- ssrf_protection_enabled: bool = False
+ ssrf_protection_enabled: bool = True
#13395: adds lfx.utils.ssrf_requests.ssrf_safe_get (per-hop validation and pinning for requests) and uses it in RSS Reader and SearXNG.
- response = requests.get(self.rss_url, timeout=self.timeout)
+ response = ssrf_safe_get(self.rss_url, timeout=self.timeout)
#13643: adds lfx.utils.ssrf_httpx (ssrf_safe_httpx_get/post, protected client kwargs) and applies it to Home Assistant, Glean and the model-provider base-URL components.
#14033: Docling Serve builds its httpx.Client with ssrf_protected_httpx_client_kwargs_for_url(base_url).
#14071 (release-1.10.3) / #14073 (forward-port to 1.11.0): Web Search validates and pins each result URL before fetching it, with redirects disabled.
Note: connector-style components (for example Home Assistant, Ollama, LM Studio) keep a documented loopback exemption (#14146), so a self-hosted user can reach a local service on localhost. Private-network and metadata addresses stay blocked. Operators can tighten or relax this with LANGFLOW_SSRF_ALLOWED_HOSTS and LANGFLOW_CONNECTOR_SSRF_VALIDATION_ENABLED.
langflow >= 1.10.3 (or langflow-base >= 0.10.3 / lfx >= 1.10.3 / lfx-docling >= 0.1.2).LANGFLOW_SSRF_PROTECTION_ENABLED=false. If you need to reach internal hosts on purpose, allowlist only those hosts with LANGFLOW_SSRF_ALLOWED_HOSTS.169.254.169.254 and use IMDSv2 on AWS).