CVE-2026-26019
Improper URL Validation in LangChain RecursiveUrlLoader Enables SSRF
Publication date: 2026-02-11
Last updated on: 2026-02-19
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| langchain | langchain_community | to 1.1.14 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-918 | The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the RecursiveUrlLoader class of the LangChain framework prior to version 1.1.14. The class is a web crawler that follows links recursively starting from a given URL. It has a preventOutside option meant to restrict crawling to the same site as the base URL. However, the implementation used a simple string prefix check (String.startsWith()) to compare URLs, which does not properly validate URLs semantically.
Because of this, an attacker controlling content on a crawled page could insert links to domains that share a string prefix with the target domain, tricking the crawler into following links to attacker-controlled or internal infrastructure. Additionally, the crawler did not validate against private or reserved IP addresses, allowing it to fetch links pointing to cloud metadata services, localhost, or RFC 1918 addresses without restriction.
This flaw could lead to unintended crawling of malicious or sensitive internal resources. The vulnerability was fixed in version 1.1.14.
How can this vulnerability impact me? :
This vulnerability can impact you by allowing an attacker to manipulate the web crawler to access unintended domains or internal network resources. This could lead to exposure of sensitive internal infrastructure or cloud metadata services that are normally protected.
Such unauthorized crawling could result in information disclosure, potentially leaking internal IP addresses or sensitive data accessible via internal services. It may also allow attackers to use the crawler as a proxy to access restricted resources.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, upgrade the LangChain framework to version 1.1.14 or later, where the issue with RecursiveUrlLoader's URL validation is fixed.