CVE-2026-27795: LangChain Community: redirect chaining can lead to SSRF bypass via RecursiveUrlLoader
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).
References
- github.com/advisories/GHSA-mphv-75cg-56wg
- github.com/langchain-ai/langchainjs
- github.com/langchain-ai/langchainjs/commit/2812d2b2b9fd9343c4850e2ab906b8cf440975ee
- github.com/langchain-ai/langchainjs/commit/d5e3db0d01ab321ec70a875805b2f74aefdadf9d
- github.com/langchain-ai/langchainjs/pull/9990
- github.com/langchain-ai/langchainjs/releases/tag/%40langchain%2Fcommunity%401.1.14
- github.com/langchain-ai/langchainjs/releases/tag/%40langchain%2Fcommunity%401.1.18
- github.com/langchain-ai/langchainjs/security/advisories/GHSA-gf3v-fwqg-4vh7
- github.com/langchain-ai/langchainjs/security/advisories/GHSA-mphv-75cg-56wg
- nvd.nist.gov/vuln/detail/CVE-2026-27795
Code Behaviors & Features
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