Vulnerability Details CVE-2026-27795
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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 12.5%
CVSS Severity
CVSS v3 Score 4.1
References
- https://github.com/langchain-ai/langchainjs/commit/2812d2b2b9fd9343c4850e2ab906b8cf440975ee
- https://github.com/langchain-ai/langchainjs/commit/d5e3db0d01ab321ec70a875805b2f74aefdadf9d
- https://github.com/langchain-ai/langchainjs/pull/9990
- https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain%2Fcommunity%401.1.14
- https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain%2Fcommunity%401.1.18
- https://github.com/langchain-ai/langchainjs/security/advisories/GHSA-gf3v-fwqg-4vh7
- https://github.com/langchain-ai/langchainjs/security/advisories/GHSA-mphv-75cg-56wg
Products affected by CVE-2026-27795
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cpe:2.3:a:langchain:langchain_community:0.3.40
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cpe:2.3:a:langchain:langchain_community:0.3.42
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cpe:2.3:a:langchain:langchain_community:0.3.43
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cpe:2.3:a:langchain:langchain_community:0.3.44
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cpe:2.3:a:langchain:langchain_community:0.3.45
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cpe:2.3:a:langchain:langchain_community:0.3.46
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cpe:2.3:a:langchain:langchain_community:0.3.47
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cpe:2.3:a:langchain:langchain_community:0.3.48
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cpe:2.3:a:langchain:langchain_community:0.3.49
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cpe:2.3:a:langchain:langchain_community:0.3.51
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cpe:2.3:a:langchain:langchain_community:0.3.52
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cpe:2.3:a:langchain:langchain_community:0.3.53
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cpe:2.3:a:langchain:langchain_community:0.3.54
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cpe:2.3:a:langchain:langchain_community:0.3.55
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cpe:2.3:a:langchain:langchain_community:0.3.56
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cpe:2.3:a:langchain:langchain_community:0.3.57
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cpe:2.3:a:langchain:langchain_community:1.0.0
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cpe:2.3:a:langchain:langchain_community:1.0.1
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cpe:2.3:a:langchain:langchain_community:1.0.2
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cpe:2.3:a:langchain:langchain_community:1.0.4
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cpe:2.3:a:langchain:langchain_community:1.0.6
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cpe:2.3:a:langchain:langchain_community:1.0.7
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cpe:2.3:a:langchain:langchain_community:1.1.0
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cpe:2.3:a:langchain:langchain_community:1.1.10
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cpe:2.3:a:langchain:langchain_community:1.1.11
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cpe:2.3:a:langchain:langchain_community:1.1.12
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cpe:2.3:a:langchain:langchain_community:1.1.14
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cpe:2.3:a:langchain:langchain_community:1.1.16
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cpe:2.3:a:langchain:langchain_community:1.1.2
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cpe:2.3:a:langchain:langchain_community:1.1.3
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cpe:2.3:a:langchain:langchain_community:1.1.4
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cpe:2.3:a:langchain:langchain_community:1.1.5
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cpe:2.3:a:langchain:langchain_community:1.1.6
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cpe:2.3:a:langchain:langchain_community:1.1.8
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cpe:2.3:a:langchain:langchain_community:1.1.9