What is XSS in a React application?
PICTURE THIS: A SENTENCE BECOMES TOKENS
The model does not read letters like humans. It reads these pieces, then predicts the next one.
Simple meaning
Cross-site scripting injects malicious JavaScript into a page other users load.
WHY — Security instead of guessing?
Why interviewers care about Security:
who only read docs from people who shipped.
and tied to Full Stack work.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens with tokens?
Before the model can read a sentence, it goes through these steps:
- 1Cross-site scripting injects malicious
JavaScript into a page other users load.
- 2React escapes text by
default, but unsanitized HTML and dangerouslySetInnerHTML remain risky.
- 3XSS is a main
reason not to keep tokens in localStorage.
- 4Context mix
Attention looks at nearby tokens together.
- 5Next token
The model scores what should come next.
- 6Decode
IDs turn back into readable text.
EXAMPLE — See it in action
Let's see how a real sentence is tokenized (tokens may vary by model):
Note: Actual tokens and IDs depend on the tokenizer (e.g., GPT, Llama, etc.).
Key takeaway
Cross-site scripting injects malicious JavaScript into a page other users load. React escapes text by default, but unsanitized HTML and dangerouslySetInnerHTML remain risky.