SSRF in Langchain Community
CVE-2026-26019
LangChain is a framework for building LLM-powered applications. Prior to 1.1.14, the RecursiveUrlLoader class in @langchain/community is a web crawler that recursively follows links from a starting URL. Its preventOutside option (enabled by default) is intended to restrict crawling to the same site as the base URL. The implementation used String.startsWith() to compare URLs, which does not perform semantic URL validation. An attacker who controls content on a crawled page could include links to domains that share a string prefix with the target, causing the crawler to follow links to attacker-controlled or internal infrastructure. Additionally, the crawler performed no validation against private or reserved IP addresses. A crawled page could include links targeting cloud metadata services, localhost, or RFC 1918 addresses, and the crawler would fetch them without restriction. This vulnerability is fixed in 1.1.14.
Vulnerability class: SSRF (Server-Side Request Forgery)
EPSS: 0.004 (29.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N.
Affected products
- Langchain Langchain_community
- Langchain-ai Langchainjs — versions < 1.1.14
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-26019?
- CVE-2026-26019 is a medium-severity vulnerability in Langchain Community, classified under Server-Side Request Forgery (SSRF). CVSS score: 4.1/10. Published 2026-02-11.
- How severe is CVE-2026-26019?
- Medium severity. CVSS v3 base score is 4.1 out of 10.