CVE-2026-27795

The record

LangChain is a framework for building LLM-powered applications. Prior to version 1.1.8, a redirect-based Server-Side Request Forgery (SSRF) bypass exists in `RecursiveUrlLoader` in `@langchain/community`. The loader validates the initial URL but allows the underlying fetch to follow redirects automatically, which permits a transition from a safe public URL to an internal or metadata endpoint without revalidation. This is a bypass of the SSRF protections introduced in 1.1.14 (CVE-2026-26019). Users should upgrade to `@langchain/community` 1.1.18, which validates every redirect hop by disabling automatic redirects and re-validating `Location` targets before following them. In this version, automatic redirects are disabled (`redirect: "manual"`), each 3xx `Location` is resolved and validated with `validateSafeUrl()` before the next request, and a maximum redirect limit prevents infinite loops.

Affected packages

Related vulnerabilities

• GHSA-gf3v-fwqg-4vh7 @langchain/community affected by SSRF Bypass in RecursiveUrlLoader via insufficient URL… Same vulnerability
• GHSA-mphv-75cg-56wg LangChain Community: redirect chaining can lead to SSRF bypass via RecursiveUrlLoader Same vulnerability
• CVE-2026-26019 LangChain is a framework for building LLM-powered applications. Also affects @langchain/community
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• CVE-2026-87953 Server-Side Request Forgery (SSRF) vulnerability in Drupal SAML SSO - Service Provider… CWE-918
• CVE-2026-114634 WWBN AVideo before 29.4.0 contains a blind server-side request forgery vulnerability in… CWE-918
• CVE-2026-112288 Krayin CRM 2.2.5 before 2.2.7 contains a server-side request forgery filter bypass that… CWE-918
• CVE-2026-111936 Sigma File Manager through 2.2.0 contains a server-side request forgery vulnerability… CWE-918