Security Report Summary
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Site: https://docs.readthedocs.com/platform/stable/guides/custom-domains.html
IP Address: 104.16.254.120
Report Time: 08 Oct 2026 10:02:47 UTC
Headers:
  • Referrer-Policy
  • X-Content-Type-Options
  • Content-Security-Policy
  • X-Frame-Options
  • Permissions-Policy
  • Strict-Transport-Security
Advanced:
Your site could be at risk, let’s perform a deeper security analysis of your site and APIs:
Missing Headers
Content-Security-PolicyContent Security Policy is an effective measure to protect your site from XSS attacks. By whitelisting sources of approved content, you can prevent the browser from loading malicious assets.
X-Frame-OptionsX-Frame-Options tells the browser whether you want to allow your site to be framed or not. By preventing a browser from framing your site you can defend against attacks like clickjacking. Recommended value "X-Frame-Options: SAMEORIGIN".
Permissions-PolicyPermissions Policy is a new header that allows a site to control which features and APIs can be used in the browser.
Warnings
Strict-Transport-SecurityThe "max-age" directive is too small. The minimum recommended value is 2592000 (30 days).
Raw Headers
HTTP/2200
dateThu, 08 Oct 2026 10:02:47 GMT
content-typetext/html; charset=utf-8
cf-raya4744fdd5e5d7dcf-DUB
cf-cache-statusREVALIDATED
access-control-allow-origin*
cache-controlmax-age=1800, stale-if-error=86400, public
content-encodinggzip
etag"72a2fb4b218798f013d195802acdbdf8"
expiresThu, 08 Oct 2026 10:32:47 GMT
last-modifiedTue, 06 Oct 2026 15:55:34 GMT
servercloudflare
x-servedNginx-Proxito-Sendfile
strict-transport-securitymax-age=3600
varyAccept-Encoding
access-control-allow-methodsHEAD, OPTIONS, GET
cdn-cache-controlpublic, max-age=1800, stale-if-error=86400
cross-origin-opener-policysame-origin
referrer-policyno-referrer-when-downgrade
x-amz-id-2cS3Hpmz2iMmmtaDd7/1P1hr6viLwHeL4Atv12fzOwX4pLbI8JiY6VfHbE84WVcpmtr++ALDreVaCN2AS0wwmqOUqWds2fOLq
x-amz-meta-mtime1791302106.556704323
x-amz-request-idK808STT8NK29SA0S
x-amz-server-side-encryptionAES256
x-backendweb-i-05b45ad192774ceeb
x-content-type-optionsnosniff
x-rtd-domaindocs.readthedocs.com
x-rtd-force-addonstrue
x-rtd-path/proxito/html/docs/stable/guides/custom-domains.html
x-rtd-projectdocs
x-rtd-project-methodcustom_domain
x-rtd-resolver-filename/guides/custom-domains.html
x-rtd-versionstable
x-rtd-version-methodpath
set-cookie_cfuvid=KClv7WH1jMhHmM_Lfk6s_hwCboJIRkIonzMUTo6_7ug-1791453767.2589612-1.0.1.1-KAbqSRkfoh__tN_E_nyfyLDji8pvu8_kA_tVtS5qXWo; HttpOnly; SameSite=None; Secure; Path=/; Domain=docs.readthedocs.com
set-cookie__cf_bm=Yv9GoRcQR.DqddIv3_X4tUO0FrvmPs.DWiboqFLYgJw-1791453767.251318-1.0.1.1-D71b2zLkqN2ymgQDJ6kFttT1GOzCAGutVLHLGS9976X72.nAdATRGkpCZ_ujBFSKCtovX.z.81YNntSJMqJEPtZx9xpHeYv1R8eUUFPltOJyEoAUgjCmsREDOrkkkYKt; HttpOnly; SameSite=None; Secure; Path=/; Domain=docs.readthedocs.com; Expires=Thu, 08 Oct 2026 10:32:47 GMT
alt-svch3=":443"; ma=86400
Upcoming Headers
Cross-Origin-Embedder-PolicyCross-Origin Embedder Policy allows a site to prevent assets being loaded that do not grant permission to load them via CORS or CORP.
Cross-Origin-Resource-PolicyCross-Origin Resource Policy allows a resource owner to specify who can load the resource.
Additional Information
access-control-allow-originThis is a very lax CORS policy. Such a policy should only be used on a public CDN.
serverServer value has been changed. Typically you will see values like "Microsoft-IIS/8.0" or "nginx 1.7.2".
strict-transport-securityHTTP Strict Transport Security is an excellent feature to support on your site and strengthens your implementation of TLS by getting the User Agent to enforce the use of HTTPS.
cross-origin-opener-policyCross-Origin Opener Policy allows a site to opt-in to Cross-Origin Isolation in the browser.
referrer-policyReferrer Policy is a new header that allows a site to control how much information the browser includes with navigations away from a document and should be set by all sites.
x-content-type-optionsX-Content-Type-Options stops a browser from trying to MIME-sniff the content type and forces it to stick with the declared content-type. The only valid value for this header is "X-Content-Type-Options: nosniff".