CVE-2026-27795
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account, but needs a user to act. Limited direct impact.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 4.1 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-918 · Server-side request forgery
- Record status
- Analyzed
Affected
- Langchain Community < 1.1.18
Attack profile CVSS 3.1 · 4.1
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-27795.md and follow it. Check whether this project is affected by CVE-2026-27795. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- 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
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