link-preview-js DNS Rebinding SSRF Bypass / Incomplete Fix for CVE-2026-43897
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.4%
exploitation probability
0.4%top 66% of all CVEs
observed exploitation
nono source reports it
Link Preview JS extracts web links information. Prior to 4.0.4, the resolveDNSHost mitigation in index.ts validates one resolved IP address but fetches the original hostname, allowing an attacker-controlled DNS server to return a public address during validation and a loopback or internal address during the final connection. This DNS rebinding condition bypasses the SSRF protection and can cause the server-side preview fetch to reach internal HTTP resources. Redirect handling is affected by the same validation-to-fetch mismatch. This issue is fixed in version 4.0.4.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Affected products
OP-Engineering · link-preview-jsReferences
https://github.com/OP-Engineering/link-preview-js/commit/6ee25043dd60b097eb70b4ce049aac94b28239e3https://github.com/OP-Engineering/link-preview-js/commit/f3a3dd84adbb9d32d06a933f44ff3eaa837f9a12https://github.com/OP-Engineering/link-preview-js/pull/181https://github.com/OP-Engineering/link-preview-js/releases/tag/4.0.4https://github.com/OP-Engineering/link-preview-js/security/advisories/GHSA-cpjf-6666-r8fx