CVE-2026-27795LangChain Community: redirect chaining can lead to SSRF bypass via RecursiveUrlLoader
- 4.1MediumCVSS base score
- 0.25%Exploitation in 30 daysEPSS · top 84% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By GitHub_M
- 1 day later
· 1 day later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium4.1 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N |
| NVDNVD · Analyzed | 3.1 | High7.4 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.25% · top 84% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.1.
Affected products
- affected < 1.1.18
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- npm@langchain/communityGHSA-mphv-75cg-56wg (opens in a new tab)
References
References7
- https://github.com/langchain-ai/langchainjs/security/advisories/GHSA-mphv-75cg-56wg (opens in a new tab)x_refsource_CONFIRM
- https://github.com/langchain-ai/langchainjs/security/advisories/GHSA-gf3v-fwqg-4vh7 (opens in a new tab)x_refsource_MISC
- https://github.com/langchain-ai/langchainjs/pull/9990 (opens in a new tab)x_refsource_MISC
- https://github.com/langchain-ai/langchainjs/commit/2812d2b2b9fd9343c4850e2ab906b8cf440975ee (opens in a new tab)x_refsource_MISC
- https://github.com/langchain-ai/langchainjs/commit/d5e3db0d01ab321ec70a875805b2f74aefdadf9d (opens in a new tab)x_refsource_MISC
- https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain%2Fcommunity%401.1.14 (opens in a new tab)x_refsource_MISC
- https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain%2Fcommunity%401.1.18 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-8697 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-mphv-75cg-56wg (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-27795)Record last updated .