link-preview-js DNS Rebinding SSRF Bypass / Incomplete Fix for CVE-2026-43897

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2026-61704: 0.55% estimated exploitation activity in the next 30 days; percentile 46.07 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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.

Published by the source

2 Sep 2026, 21:29 UTC

Last modified by the source

2 Sep 2026, 21:30 UTC

Source last checked

26 Oct 2026, 13:02 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-cpjf-6666-r8fx

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# Patch Next advisory brief: CVE-2026-61704

Advisory: link-preview-js DNS Rebinding SSRF Bypass / Incomplete Fix for CVE-2026-43897
IDs: CVE-2026-61704, GHSA-cpjf-6666-r8fx
Record: https://patchnext.com/advisories/cve-2026-61704 (revision 1, source checked 26 Oct 2026, 13:02 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: link-preview-js 4.0.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm link-preview-js: affected <= 4.0.3; fixed in 4.0.4

## Suggested inspection (read-only)
- `npm ls link-preview-js --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on link-preview-js.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-cpjf-6666-r8fx (GitHub-reviewed advisory GHSA-cpjf-6666-r8fx lists affected ranges: npm link-preview-js >=0 <=4.0.3)

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