What is the HttpOnly cookie flag?

It prevents JavaScript from accessing the cookie, stopping XSS-based theft.

How to check if a site misses HttpOnly?

Inspect cookies in browser dev tools or use curl; look for absence in Set-Cookie header.

Does adding HttpOnly fix all session hijacks?

No—it blocks XSS reads but pair with Secure, SameSite, and HTTPS for full cover.

The One Cookie Flag Hackers Love — And Why Devs Still Miss It

Ever wonder why your login session vanishes after an XSS attack? It's often one overlooked flag: HttpOnly. This daily cybersecurity dive reveals the stakes.

theAIcatchup Apr 09, 2026 3 min read

Broken cookie with missing HttpOnly flag leading to session hijacking attack

⚡ Key Takeaways

Missing HttpOnly on session cookies enables trivial XSS hijacking — fix with one flag. 𝕏
DNS TXT records reveal email spoofing risks; no SPF means BEC playground. 𝕏
Python loops underpin sec tools — start simple, scale to scanners. 𝕏

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theAIcatchup

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#DNS security #HttpOnly flag #XSS vulnerability #cookie security #session hijacking

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Originally reported by dev.to

⚡ Key Takeaways

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