gchq/CyberChef

bug(From BCD): Uncaught TypeError can'nt access property indexOf, n is undefined

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#2,489 opened on Jun 4, 2026

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 (0 comments) (0 reactions) (0 assignees)JavaScript (3,944 forks)batch import
bughelp wanted

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Description

To reproduce that use a direct url https://gchq.github.io/CyberChef/#recipe=From_BCD('',true,false,'Nibbles')&input=MTAwMA&oeol=VT, then as you can see

From BCD - TypeError in blob:https://gchq.github.io/7f68ce91-b78c-4bad-92a1-2f639f10c891 on line 2.<br><br>Message: can't access property "indexOf", n is undefined

the issue is simple issue the first parameter not checked is empty or not, that persists, because after that a code try to use indexOf in n, and simply n is undefined, will throw an error

Contributor guide

Research direction
Inspect the FromBCD function and add a check for undefined input before calling .indexOf.
Tech stack
javascript
Domain
frontend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
JavaScript
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
80