FKIE_CVE-2026-27795

Vulnerability from fkie_nvd - Published: 2026-02-25 18:23 - Updated: 2026-02-25 18:23
Severity ?
4.1 (Medium) - CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N
Summary
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.
References
security-advisories@github.comhttps://github.com/langchain-ai/langchainjs/commit/2812d2b2b9fd9343c4850e2ab906b8cf440975ee
security-advisories@github.comhttps://github.com/langchain-ai/langchainjs/commit/d5e3db0d01ab321ec70a875805b2f74aefdadf9d
security-advisories@github.comhttps://github.com/langchain-ai/langchainjs/pull/9990
security-advisories@github.comhttps://github.com/langchain-ai/langchainjs/releases/tag/%40langchain%2Fcommunity%401.1.14
security-advisories@github.comhttps://github.com/langchain-ai/langchainjs/releases/tag/%40langchain%2Fcommunity%401.1.18
security-advisories@github.comhttps://github.com/langchain-ai/langchainjs/security/advisories/GHSA-gf3v-fwqg-4vh7
security-advisories@github.comhttps://github.com/langchain-ai/langchainjs/security/advisories/GHSA-mphv-75cg-56wg
Impacted products
Vendor Product Version
To clipboard 

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "id": "CVE-2026-27795",
  "lastModified": "2026-02-25T18:23:41.153",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 4.1,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "CHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.3,
        "impactScore": 1.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-02-25T18:23:41.153",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/langchain-ai/langchainjs/commit/2812d2b2b9fd9343c4850e2ab906b8cf440975ee"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/langchain-ai/langchainjs/commit/d5e3db0d01ab321ec70a875805b2f74aefdadf9d"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/langchain-ai/langchainjs/pull/9990"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain%2Fcommunity%401.1.14"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/langchain-ai/langchainjs/releases/tag/%40langchain%2Fcommunity%401.1.18"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/langchain-ai/langchainjs/security/advisories/GHSA-gf3v-fwqg-4vh7"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/langchain-ai/langchainjs/security/advisories/GHSA-mphv-75cg-56wg"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-918"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.