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GHSA-CPJF-6666-R8FX

Vulnerability from github – Published: 2026-09-02 21:29 – Updated: 2026-09-02 21:29
VLAI
Summary
link-preview-js DNS Rebinding SSRF Bypass / Incomplete Fix for CVE-2026-43897
Details

The existing advisory GHSA-4gp8-rjrq-ch6q / CVE-2026-43897 states that the SSRF issue was fixed in 4.0.1. However, 4.0.3 remains bypassable when the documented resolveDNSHost mitigation is used.

Root cause: The library validates one resolved IP address through resolveDNSHost, but later performs fetch() against the original hostname without pinning the connection to the validated IP. An attacker-controlled DNS server can return a public IP during validation and a loopback/internal IP during the final connection.

Impact: This allows an attacker to bypass the documented SSRF mitigation and make the server-side fetch reach loopback or internal addresses under DNS rebinding conditions.

This appears to be either an incomplete fix for CVE-2026-43897 or a new DNS rebinding SSRF bypass affecting the latest version.

The PoC was reproduced in a local-only controlled environment to avoid targeting production or third-party systems. Evidence and reproduction details can be provided privately.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Show details on source website
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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 4.0.3"
      },
      "package": {
        "ecosystem": "npm",
        "name": "link-preview-js"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.0.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-61704"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-02T21:29:57Z",
    "nvd_published_at": "2026-08-20T17:18:51Z",
    "severity": "HIGH"
  },
  "details": "The existing advisory GHSA-4gp8-rjrq-ch6q / CVE-2026-43897 states that the SSRF issue was fixed in 4.0.1. However, 4.0.3 remains bypassable when the documented resolveDNSHost mitigation is used.\n\nRoot cause:\nThe library validates one resolved IP address through resolveDNSHost, but later performs fetch() against the original hostname without pinning the connection to the validated IP. An attacker-controlled DNS server can return a public IP during validation and a loopback/internal IP during the final connection.\n\nImpact:\nThis allows an attacker to bypass the documented SSRF mitigation and make the server-side fetch reach loopback or internal addresses under DNS rebinding conditions.\n\nThis appears to be either an incomplete fix for CVE-2026-43897 or a new DNS rebinding SSRF bypass affecting the latest version.\n\nThe PoC was reproduced in a local-only controlled environment to avoid targeting production or third-party systems. Evidence and reproduction details can be provided privately.",
  "id": "GHSA-cpjf-6666-r8fx",
  "modified": "2026-09-02T21:29:57Z",
  "published": "2026-09-02T21:29:57Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/OP-Engineering/link-preview-js/security/advisories/GHSA-cpjf-6666-r8fx"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-61704"
    },
    {
      "type": "WEB",
      "url": "https://github.com/OP-Engineering/link-preview-js/pull/181"
    },
    {
      "type": "WEB",
      "url": "https://github.com/OP-Engineering/link-preview-js/commit/6ee25043dd60b097eb70b4ce049aac94b28239e3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/OP-Engineering/link-preview-js/commit/f3a3dd84adbb9d32d06a933f44ff3eaa837f9a12"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/OP-Engineering/link-preview-js"
    },
    {
      "type": "WEB",
      "url": "https://github.com/OP-Engineering/link-preview-js/releases/tag/4.0.4"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "link-preview-js DNS Rebinding SSRF Bypass / Incomplete Fix for CVE-2026-43897"
}



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