Home Categories networking Products npm npm SSL certificate is untrusted or leaf signature cannot be verified npm
npm SSL certificate is untrusted or leaf signature cannot be verified npm ERR! Error: SSL Error: CERT_UNTRUSTED / UNABLE_TO_VERIFY_LEAF_SIGNATURE npm could not validate the TLS certificate chain for the registry connection, often because of outdated runtime support, custom CA issues, or an inspecting proxy.
Observed message
npm ERR! Error: SSL Error: CERT_UNTRUSTED / UNABLE_TO_VERIFY_LEAF_SIGNATURE Why it happens
The runtime or npm client does not trust the presented certificate chain. Custom CA or registry TLS settings are incomplete or incorrect. A proxy is intercepting SSL traffic and presenting a certificate npm does not trust. How to fix it
Upgrade the runtime or npm client if certificate handling is outdated. Review npm CA configuration and align it with the certificate chain in use. Investigate whether a proxy is rewriting TLS connections. 