fast-uri npm Package Vulnerability: Host Confusion via Failed IDN Canonicalization
An early warning has been issued regarding the fast-uri npm package versions >=2.3.1, <=4.0.0, which reportedly fail to canonicalize Unicode/IDN hostnames for HTTP-family URLs. This appears to result in host-based policy desync and unintended routing.
What happened
The fast-uri npm package, specifically versions >=2.3.1 and <=4.0.0, is under investigation for a vulnerability that involves the failure to canonicalize Unicode/IDN hostnames in HTTP-family URLs. This issue may lead to host-based policy desync and unintended routing of network traffic. To mitigate this potential threat, it is recommended to upgrade to fast-uri v4.0.1, v3.1.3, or v2.4.2. Professional software engineers assessing their exposure should review their dependencies and consider upgrading affected components. For more detailed information, consult the primary sources provided.
How 0Day mitigates this
fast-uri is anywhere in your dependency tree, the engineers who own the affected repositories get a push alert the moment it is flagged — no manual audit to remember to run.Read how this differs from waiting on a scanner to catch a known advisory, or see the exact, read-only access 0Day needs to do this for an organization.