Bug 2442693 (CVE-2026-27795)

Summary:	CVE-2026-27795 langchain-core: @langchain/community: Server-Side Request Forgery (SSRF) bypass via redirect manipulation
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	anpicker, bparees, dfreiber, drow, dschmidt, erezende, hasun, jburrell, jfula, jkoehler, jlanda, jowilson, jwong, kshier, lphiri, mattdavi, nyancey, omaciel, ometelka, ptisnovs, simaishi, smcdonal, stcannon, syedriko, teagle, ttakamiy, vkumar, xdharmai, yguenane
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in @langchain/community. The RecursiveUrlLoader component, which is responsible for loading URLs, fails to revalidate URLs after following redirects. This allows an attacker to bypass existing Server-Side Request Forgery (SSRF) protections by initially providing a safe public URL that then redirects to an internal or sensitive metadata endpoint. This could lead to unauthorized information disclosure or access to internal network resources.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
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Description OSIDB Bzimport 2026-02-25 18:07:34 UTC

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.