SSL/TLS Analysis for stackoverflow.com

Analyzed on November 02, 2025 at 19:09 UTC

Security Score
86 / 100

Certificate Information

Subject
CN=stackoverflow.com
Issuer
C=US, O=Let's Encrypt, CN=E7
Valid From
October 24, 2025
Valid Until
January 22, 2026 80 days
Public Key
ECDSA 256 bit (P-256) Adequate
Signature Algorithm
ECDSA-SHA384
SHA-256 Fingerprint
47:94:7D:1F:FD:1E:45:B6:DB:40:26:93:D4:EA:B0:B0:36:DC:62:94:3C:A6:24:79:45:E5:87:93:1F:2D:17:18
Alternative Names

Security Configuration

TLS Protocols
TLS 1.2 TLS 1.3
Forward Secrecy
Supported (Modern clients use PFS)

HTTP Security Headers

Status
Strict-Transport-Security
Good
max-age=31536000; includeSubDomains
Content-Security-Policy
Weak
upgrade-insecure-requests; frame-ancestors
X-Frame-Options
Good
SAMEORIGIN
X-Content-Type-Options
Missing
Not configured
Referrer-Policy
Missing
Not configured
Permissions-Policy
Missing
Not configured
Recommendations
  • Consider adding 'preload' to HSTS for maximum security
  • Significantly strengthen CSP directives
  • Add X-Content-Type-Options: nosniff
  • Add Referrer-Policy header (recommended: strict-origin-when-cross-origin)
  • Consider adding Permissions-Policy to control browser features

CAA Records (Certificate Authority Authorization)

CAA Records
Configured (Restricts certificate issuance)
Current Issuer
Authorized (Matches CAA policy)
Authorized CAs
Wildcard CAs
Incident Reporting
Recommendations
  • You have authorized 6 CAs - consider limiting to only the CAs you actively use

Subject Alternative Names

2 domains