# CVE-2026-27795: LangChain Community SSRF bypass via redirect chaining in RecursiveUrlLoader

Source: https://junglewise.ai/threats/cve-2026-27795-langchain-community-ssrf-bypass-via-redirect-chaining-in  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-02-25. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-27795 · Severity: low · CVSS 3.1 · Published 2026-02-25

LangChain Community's RecursiveUrlLoader is a web crawling component used to automatically fetch and process content from websites. An attacker can exploit a flaw in redirect handling to make the crawler access internal services, cloud metadata endpoints, or localhost—bypassing the existing security protections. This could expose sensitive credentials, tokens, or data from internal infrastructure that the crawler has access to.

Technologies: [@langchain/community (npm)](https://junglewise.ai/threats/technologies/langchain-community). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2026-27795 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-27795 being exploited in the wild.

**How severe is CVE-2026-27795?** Low severity, with a CVSS score of 3.1, published 25 February 2026.

**Which products and versions are affected?** @langchain/community (npm) SEMVER:introduced=0,fixed=1.1.18.

**Is there a fix for CVE-2026-27795?** Yes. @langchain/community (npm): upgrade to 1.1.18 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-27795 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-27795?** Check whether you run @langchain/community (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- @langchain/community (npm): upgrade to 1.1.18 or later

  ```sh
  npm install @langchain/community@1.1.18
  ```


## Technical details

The vulnerability is a Server-Side Request Forgery (SSRF) bypass in RecursiveUrlLoader that exploits automatic redirect following. The component validates the initial URL against a blocklist (private IPs, cloud metadata endpoints) but does not re-validate when HTTP 3xx redirects are followed. An attacker can supply a URL that passes initial validation, which then redirects to a blocked destination (e.g., 169.254.169.254 for AWS metadata), and the underlying fetch() call follows the redirect without triggering the SSRF checks. This is a "check-then-act" gap: validation occurs before redirect resolution. The fix disables automatic redirects (redirect: "manual"), manually validates each Location header before following it, and enforces a maximum redirect limit. Affected versions: @langchain/community <= 1.1.17; patched in 1.1.18.

## Affected products

- LangChain @langchain/community < 1.1.18

## Identifiers

- CVE-2026-27795
- GHSA-mphv-75cg-56wg

## Timeline

- 2026-02-25: disclosed
- 2026-02-25: patched: Version 1.1.18 released with fix

## References

- [https://github.com/langchain-ai/langchainjs/security/advisories/GHSA-gf3v-fwqg-4vh7](https://github.com/langchain-ai/langchainjs/security/advisories/GHSA-gf3v-fwqg-4vh7)
- [https://github.com/langchain-ai/langchainjs/security/advisories/GHSA-mphv-75cg-56wg](https://github.com/langchain-ai/langchainjs/security/advisories/GHSA-mphv-75cg-56wg)

## Related threats

- [LangChain @langchain/community SSRF bypass in RecursiveUrlLoader](https://junglewise.ai/threats/cve-2026-26019-langchain-langchain-community-ssrf-bypass-in-recursiveurlloader)
- [LangChain Community SQL injection in GraphCypherQAChain](https://junglewise.ai/threats/cve-2024-7042-langchain-community-sql-injection-in-graphcypherqachain)