NET::ERR_CERT_WEAK_SIGNATURE_ALGORITHM
NET::ERR_CERT_WEAK_SIGNATURE_ALGORITHM Error
What This Error Means
The NET::ERR_CERT_WEAK_SIGNATURE_ALGORITHM error occurs when the website's SSL certificate was signed using a cryptographic algorithm that is no longer considered secure, such as SHA-1. Browsers block these certificates because they are vulnerable to collision attacks.
Common Causes
- The certificate was issued years ago and has not been renewed.
- The server is using a self-signed certificate generated with default (old) settings.
- An intermediate certificate in the chain is using a weak algorithm.
- Corporate interception proxies generating weak certificates on the fly.
How to Fix It (For Users)
- 1 Do not proceed if you are on a public network.
- 2 If on a corporate network, contact IT support.
- 3 Update your browser to ensure it has the latest security policies.
For Site Owners / Developers
- Reissue your SSL certificate using SHA-256 (SHA-2) or better.
- Check your entire certificate chain for weak intermediates.
- Ensure your CSR (Certificate Signing Request) specifies a strong signature algorithm.
- Stop using SHA-1 for any public-facing certificates.
When It Is NOT Your Fault
If the website is using an ancient certificate.
Check if this outage affects everyone globally
This error often indicates a wider problem. Use our tool to verify if the site is down for everyone.
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