CVE-2026-43897 — link-preview-js
Fix: OP-Engineering/link-preview-js@4396d48CVE-2026-43897 is a Server-Side Request Forgery (SSRF) vulnerability in link-preview-js. A fix is available for link-preview-js — see the affected versions and patch details below.
Link Preview JS: vunerable to IPv6 and internal loopback attacks
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-43897.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
link-preview-jsnpmDescription
Impact
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.
Patches
Problem has been patched in version 4.0.1. However, it cannot be completely solved by the package alone. The regex used for validation has been tightened for IPv6 addresses.
The DNS resolving, however, is more difficult. The regex has been tightened to prohibit .internal, .local, .nip.io and .sslip.io addresses, however there can be other services not on the list, therefore it is imperative that users use the resolveDNSHost option to do DNS resolution before fetching content. To that regard a (scary) error message has been added when the option is not set.
Workarounds
Users can do their own validation before fetching content.
Reported by https://github.com/Andrew-most-likely
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | link-preview-js | all versions | 4.0.1npm install link-preview-js@4.0.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for link-preview-js, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update link-preview-js to 4.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-43897 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-43897 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-43897. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-43897 in your dependencies?
O3 Security finds CVE-2026-43897 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.