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Graph/cookie-domain-samesite-mismatch

Pattern

Cookie Domain And SameSite Drift

cookie-domain-samesite-mismatch

Cross-subdomain and cross-site browser cookie behavior fails because Session/CSRF-relevant cookies are set with restrictive domain and SameSite defaults, so the browser omits them on redirects and API calls, breaking auth and payments flows.

Node Details

Public graph metadata

Updated8/3/2026

Connections

30 linked nodes

Cookie “__vercel_live_token” has been rejected because it is in a cross-site context and its “SameSite” is “Lax” or “Strict” — deployed it on Vercel. Tension: But i setup cookies in my project like this. Outcome: Then you need to use https://localhost:5000 and not http://localhost:5000.

When the UI calls the `POST /auth/callback/passkey` endpoint. Tension: Origin servers SHOULD NOT fold multiple Set-Cookie header fields into a single header field. Outcome: Cloudflare seem to be in the wrong here.

when I refresh my page the cookie gets deleted — I have deployed my sveltekit frontend and python flask backend on vercel. Tension: On localhost, they worked just fine however when I deployed it, the cookies were not persistent. Outcome: it does sets the cookie, but on refresh, the cookie gets disappeared.

Using Fetch from my `index.html` from my `portal.mydomain.com` does not. — Enter `api.mydomain.com` into a browser directly does save my cookie. Tension: I have no CORS errors and the OPTIONS, GET and POST requests all get a 200 response. Outcome: just no cookie, nor can I see the cookie set in my broswer dev tools.

RedirectResponse goes to "/" without the authentication cookie

AADSTS9002325: Proof Key for Code Exchange is required for cross-origin authorization code redemption. Tension: redirects uris not matching.

SessionMiddleware in a FastAPI backend fails to set the session cookie when the React frontend and backend are hosted on different domains/subdomains (e.g., XXX-ui.fly.dev vs XXX-api.fly.dev). The browser rejects the cookie with an 'invalid domain' error and no session is maintained.

were not accessible in js and in browser — Cookies are being set and sent with the next request. Outcome: The problem solved by adding `domain="blueberry.adefe.xyz"` to the cookie in response.

$_SESSION['eepasts'] is empty after Stripe payment redirect

The someone can easily append this query string to end of the page or fake the http referer to pretende to have paid for the product — in my getServerSideProps() function in my page, which is redirect from check out as determined by success_url. Tension: I need a server side check too. Outcome: How can I do that?

Failed to fetch /api/auth/csrf — while integrating it with Keycloak and a custom base path. Tension: Verified the csrf endpoint manually, but it appears to be unreachable. Outcome: I solved it by manually signout.

Embedding a CPQ web app as an iframe inside Salesforce fails to persist authentication cookies/session for API calls. Login in a new tab isn’t recognized inside the Salesforce iframe, preventing authorized requests.

the cookie will be specifically set with `domain=app.sunsetland.com.au`. Tension: if we were to host another subdomain aside from `app.`, we actually would likely encounter the reCAPTCHA challenge again.

REST API rejects browser client requests when Content Security Policy is not configured to allow the requesting site

can I create, from 2. and 3. a server side httpOnly cookie (containing a `widget_id`) of domain `mycompany-example.com`, that can be used during step 5. Outcome: when the user visits our website so we know which widget they come from ?

Client-side double-submit CSRF token generation is vulnerable to subdomain hijacking

Confusion about cookie authentication versus token authentication

httpOnly cookies are the best way to store tokens safely and protect them from XSS attacks — storing JWTs on the client. Tension: JavaScript won't be allowed to read httpOnly cookies. How would the client handle routes authentication? Outcome: The browser won't automatically set the `Authorization` header like it does with cookies.

the browser prevents a potential CSRF attack and doesn't include the token — The call is to the backend endpoint specified earlier in `redirect_uri`. Tension: I need a browser to include the `ASP.NET_SessionId` cookie in the request. Outcome: If I set the `SameSite` cookie attribute to `None` the endpoint can be reached.

on Chrome I get an error saying that the CSRF token is mismatched — show a third-party web page (with their approval) in an iframe. Tension: This site has a different domain to my parent site. Outcome: The site displays fine on firefox.

If I check 'Remember Me' in form, this add a cookie with name "REMEMBERME". Tension: I'm implementing custom authenticator. Outcome: your cookie is normal.

The session identifier (req.sessionID) changed on every subsequent HTTP request from the React client to the Express server, preventing consistent session persistence.

Browser requests to the PHP API from a React/Vite app fail with a CORS error when an Authorization header is included. Requests without custom headers work correctly.

Accessing https://example.com results in a “too many redirects” loop, while other domain variants redirect correctly for a React app served by Apache with Cloudflare-managed DNS/SSL.

After signing in, middleware redirection occurs, but the browser URL remains unchanged (e.g., it doesn't update to the intended callback/protected route).

The browser does not store the refresh token cookie returned by the Django Ninja login endpoint, even though the cookie appears in the response headers and the fetch call uses credentials: 'include'.

one is working without any credential or cookie[SessionId] but another one is not working — two api's in my spring mvc project which have identical structure. Tension: while calling using Postman or while hitting the APIs in browser/UI project.

Requests to the Django/DRF backend fail with “CSRF Failed: Origin checking failed - http://localhost:8000/ does not match any trusted origins.”

Tor ecommerce platform missing security headers and CSRF protection — Tor ecommerce platform. Tension: missing security headers and CSRF protection.

throws "Cookies can only be modified in a Server Action or Route Handler" — called from Next.js 15 Server Components (pages, layouts). Tension: The error appears intermittently — only when the session needs refreshing (controlled by `updateAge` config). Outcome: With `updateAge: 300` (5 minutes), it crashes every ~5 minutes for active users.

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